diff --git a/demo/sdl3_renderer/main.c b/demo/sdl3_renderer/main.c
index 1d8cdce7..661331a1 100644
--- a/demo/sdl3_renderer/main.c
+++ b/demo/sdl3_renderer/main.c
@@ -75,8 +75,9 @@
 #define NK_VSNPRINTF(s, n, f, a)  SDL_vsnprintf(s, n, f, a)
 #define NK_STRTOD(str, endptr)    SDL_strtod(str, endptr)
 
-/* sadly, SDL3 does not provide "dtoa" (only integer version) */
-/*#define NK_DTOA (str, d)*/
+/* HACK: SDL3 does not provide "dtoa" (only integer version)
+ * so we use sprintf with %g formatting to get almost the same result */
+#define NK_DTOA(str, d) (SDL_snprintf(str, 999, "%g", d), str)
 
 /* SDL can also provide us with math functions, but beware that Nuklear's own
  * implementation can be slightly faster at the cost of some precision */
diff --git a/nuklear.h b/nuklear.h
index 1b13281f..1b2b9103 100644
--- a/nuklear.h
+++ b/nuklear.h
@@ -4040,6 +4040,7 @@ NK_API int nk_strtoi(const char *str, char **endptr);
 NK_API float nk_strtof(const char *str, char **endptr);
 #ifndef NK_STRTOD
 #define NK_STRTOD nk_strtod
+#define NK_STRTOD_IMPLEMENTATION
 NK_API double nk_strtod(const char *str, char **endptr);
 #endif
 NK_API int nk_strfilter(const char *text, const char *regexp);
@@ -6146,18 +6147,28 @@ NK_GLOBAL const struct nk_color nk_yellow = {255,255,0,255};
 
 /* math */
 #ifndef NK_INV_SQRT
+#define NK_INV_SQRT nk_inv_sqrt
+#define NK_INV_SQRT_IMPLEMENTATION
 NK_LIB float nk_inv_sqrt(float n);
 #endif
 #ifndef NK_SIN
+#define NK_SIN nk_sin
+#define NK_SIN_IMPLEMENTATION
 NK_LIB float nk_sin(float x);
 #endif
 #ifndef NK_COS
+#define NK_COS nk_cos
+#define NK_COS_IMPLEMENTATION
 NK_LIB float nk_cos(float x);
 #endif
 #ifndef NK_ATAN
+#define NK_ATAN nk_atan
+#define NK_ATAN_IMPLEMENTATION
 NK_LIB float nk_atan(float x);
 #endif
 #ifndef NK_ATAN2
+#define NK_ATAN2 nk_atan2
+#define NK_ATAN2_IMPLEMENTATION
 NK_LIB float nk_atan2(float y, float x);
 #endif
 NK_LIB nk_uint nk_round_up_pow2(nk_uint v);
@@ -6179,15 +6190,21 @@ NK_LIB int nk_to_upper(int c);
 NK_LIB int nk_to_lower(int c);
 
 #ifndef NK_MEMCPY
+#define NK_MEMCPY nk_memcopy
+#define NK_MEMCPY_IMPLEMENTATION
 NK_LIB void* nk_memcopy(void *dst, const void *src, nk_size n);
 #endif
 #ifndef NK_MEMSET
+#define NK_MEMSET nk_memset
+#define NK_MEMSET_IMPLEMENTATION
 NK_LIB void nk_memset(void *ptr, int c0, nk_size size);
 #endif
 NK_LIB void nk_zero(void *ptr, nk_size size);
 NK_LIB char *nk_itoa(char *s, long n);
 NK_LIB int nk_string_float_limit(char *string, int prec);
 #ifndef NK_DTOA
+#define NK_DTOA nk_dtoa
+#define NK_DTOA_IMPLEMENTATION
 NK_LIB char *nk_dtoa(char *s, double n);
 #endif
 NK_LIB int nk_text_clamp(const struct nk_user_font *font, const char *text, int text_len, float space, int *glyphs, float *text_width, nk_rune *sep_list, int sep_count);
@@ -6463,8 +6480,7 @@ nk_stbtt_free(void *ptr, void *user_data) {
 ///  (it can actually approximate a lot more functions) can be
 ///  found here: www.lolengine.net/wiki/oss/lolremez
 */
-#ifndef NK_INV_SQRT
-#define NK_INV_SQRT nk_inv_sqrt
+#ifdef NK_INV_SQRT_IMPLEMENTATION
 NK_LIB float
 nk_inv_sqrt(float n)
 {
@@ -6478,8 +6494,7 @@ nk_inv_sqrt(float n)
     return conv.f;
 }
 #endif
-#ifndef NK_SIN
-#define NK_SIN nk_sin
+#ifdef NK_SIN_IMPLEMENTATION
 NK_LIB float
 nk_sin(float x)
 {
@@ -6494,8 +6509,7 @@ nk_sin(float x)
     return a0 + x*(a1 + x*(a2 + x*(a3 + x*(a4 + x*(a5 + x*(a6 + x*a7))))));
 }
 #endif
-#ifndef NK_COS
-#define NK_COS nk_cos
+#ifdef NK_COS_IMPLEMENTATION
 NK_LIB float
 nk_cos(float x)
 {
@@ -6513,8 +6527,7 @@ nk_cos(float x)
     return a0 + x*(a1 + x*(a2 + x*(a3 + x*(a4 + x*(a5 + x*(a6 + x*(a7 + x*a8)))))));
 }
 #endif
-#ifndef NK_ATAN
-#define NK_ATAN nk_atan
+#ifdef NK_ATAN_IMPLEMENTATION
 NK_LIB float
 nk_atan(float x)
 {
@@ -6533,8 +6546,7 @@ nk_atan(float x)
     return u;
 }
 #endif
-#ifndef NK_ATAN2
-#define NK_ATAN2 nk_atan2
+#ifdef NK_ATAN2_IMPLEMENTATION
 NK_LIB float
 nk_atan2(float y, float x)
 {
@@ -6797,8 +6809,7 @@ NK_LIB nk_bool nk_is_upper(int c){return (c >= 'A' && c <= 'Z') || (c >= 0xC0 &&
 NK_LIB int nk_to_upper(int c) {return (c >= 'a' && c <= 'z') ? (c - ('a' - 'A')) : c;}
 NK_LIB int nk_to_lower(int c) {return (c >= 'A' && c <= 'Z') ? (c - ('a' + 'A')) : c;}
 
-#ifndef NK_MEMCPY
-#define NK_MEMCPY nk_memcopy
+#ifdef NK_MEMCPY_IMPLEMENTATION
 NK_LIB void*
 nk_memcopy(void *dst0, const void *src0, nk_size length)
 {
@@ -6856,8 +6867,7 @@ nk_memcopy(void *dst0, const void *src0, nk_size length)
     return (dst0);
 }
 #endif
-#ifndef NK_MEMSET
-#define NK_MEMSET nk_memset
+#ifdef NK_MEMSET_IMPLEMENTATION
 NK_LIB void
 nk_memset(void *ptr, int c0, nk_size size)
 {
@@ -6948,6 +6958,7 @@ nk_strtoi(const char *str, char **endptr)
         *endptr = (char *)p;
     return neg*value;
 }
+#ifdef NK_STRTOD_IMPLEMENTATION
 NK_API double
 nk_strtod(const char *str, char **endptr)
 {
@@ -7005,6 +7016,7 @@ nk_strtod(const char *str, char **endptr)
         *endptr = p;
     return number;
 }
+#endif
 NK_API float
 nk_strtof(const char *str, char **endptr)
 {
@@ -7283,8 +7295,7 @@ nk_itoa(char *s, long n)
     nk_strrev_ascii(s);
     return s;
 }
-#ifndef NK_DTOA
-#define NK_DTOA nk_dtoa
+#ifdef NK_DTOA_IMPLEMENTATION
 NK_LIB char*
 nk_dtoa(char *s, double n)
 {
@@ -28950,7 +28961,7 @@ nk_do_property(nk_flags *ws,
             break;
         case NK_PROPERTY_DOUBLE:
             nk_string_float_limit(buffer, NK_MAX_FLOAT_PRECISION);
-            variant->value.d = nk_strtod(buffer, 0);
+            variant->value.d = NK_STRTOD(buffer, 0);
             variant->value.d = NK_CLAMP(variant->min_value.d, variant->value.d, variant->max_value.d);
             break;
         }
@@ -30731,6 +30742,11 @@ nk_tooltipfv(struct nk_context *ctx, const char *fmt, va_list args)
 ///   - [y]: Minor version with non-breaking API and library changes
 ///   - [z]: Patch version with no direct changes to the API
 ///
+/// - 2025/11/18 (4.13.1) - Fix: nk_do_property now uses NK_STRTOD via macro
+///                       - Fix: failure to build from source, due to
+///                         nuklear_math/util.c not declaring some functions
+///                       - Fix: guard nk_strtod implementation with preprocessor
+///                       - Fix: nuklear_sdl3_renderer now provides NK_DTOA
 /// - 2025/11/15 (4.13.0) - Fix: nk_property not updating 'win->edit.active'
 ///                         Add new updated demo: sdl3_renderer
 /// - 2025/10/08 (4.12.8) - Fix nk_widget_text to use NK_TEXT_ALIGN_LEFT by default,
diff --git a/src/CHANGELOG b/src/CHANGELOG
index 8de53d80..05034f90 100644
--- a/src/CHANGELOG
+++ b/src/CHANGELOG
@@ -7,6 +7,11 @@
 ///   - [y]: Minor version with non-breaking API and library changes
 ///   - [z]: Patch version with no direct changes to the API
 ///
+/// - 2025/11/18 (4.13.1) - Fix: nk_do_property now uses NK_STRTOD via macro
+///                       - Fix: failure to build from source, due to
+///                         nuklear_math/util.c not declaring some functions
+///                       - Fix: guard nk_strtod implementation with preprocessor
+///                       - Fix: nuklear_sdl3_renderer now provides NK_DTOA
 /// - 2025/11/15 (4.13.0) - Fix: nk_property not updating 'win->edit.active'
 ///                         Add new updated demo: sdl3_renderer
 /// - 2025/10/08 (4.12.8) - Fix nk_widget_text to use NK_TEXT_ALIGN_LEFT by default,
diff --git a/src/nuklear.h b/src/nuklear.h
index 9362e816..c14eca3c 100644
--- a/src/nuklear.h
+++ b/src/nuklear.h
@@ -3817,6 +3817,7 @@ NK_API int nk_strtoi(const char *str, char **endptr);
 NK_API float nk_strtof(const char *str, char **endptr);
 #ifndef NK_STRTOD
 #define NK_STRTOD nk_strtod
+#define NK_STRTOD_IMPLEMENTATION
 NK_API double nk_strtod(const char *str, char **endptr);
 #endif
 NK_API int nk_strfilter(const char *text, const char *regexp);
diff --git a/src/nuklear_internal.h b/src/nuklear_internal.h
index a1523e8e..c6e5a579 100644
--- a/src/nuklear_internal.h
+++ b/src/nuklear_internal.h
@@ -95,18 +95,28 @@ NK_GLOBAL const struct nk_color nk_yellow = {255,255,0,255};
 
 /* math */
 #ifndef NK_INV_SQRT
+#define NK_INV_SQRT nk_inv_sqrt
+#define NK_INV_SQRT_IMPLEMENTATION
 NK_LIB float nk_inv_sqrt(float n);
 #endif
 #ifndef NK_SIN
+#define NK_SIN nk_sin
+#define NK_SIN_IMPLEMENTATION
 NK_LIB float nk_sin(float x);
 #endif
 #ifndef NK_COS
+#define NK_COS nk_cos
+#define NK_COS_IMPLEMENTATION
 NK_LIB float nk_cos(float x);
 #endif
 #ifndef NK_ATAN
+#define NK_ATAN nk_atan
+#define NK_ATAN_IMPLEMENTATION
 NK_LIB float nk_atan(float x);
 #endif
 #ifndef NK_ATAN2
+#define NK_ATAN2 nk_atan2
+#define NK_ATAN2_IMPLEMENTATION
 NK_LIB float nk_atan2(float y, float x);
 #endif
 NK_LIB nk_uint nk_round_up_pow2(nk_uint v);
@@ -128,15 +138,21 @@ NK_LIB int nk_to_upper(int c);
 NK_LIB int nk_to_lower(int c);
 
 #ifndef NK_MEMCPY
+#define NK_MEMCPY nk_memcopy
+#define NK_MEMCPY_IMPLEMENTATION
 NK_LIB void* nk_memcopy(void *dst, const void *src, nk_size n);
 #endif
 #ifndef NK_MEMSET
+#define NK_MEMSET nk_memset
+#define NK_MEMSET_IMPLEMENTATION
 NK_LIB void nk_memset(void *ptr, int c0, nk_size size);
 #endif
 NK_LIB void nk_zero(void *ptr, nk_size size);
 NK_LIB char *nk_itoa(char *s, long n);
 NK_LIB int nk_string_float_limit(char *string, int prec);
 #ifndef NK_DTOA
+#define NK_DTOA nk_dtoa
+#define NK_DTOA_IMPLEMENTATION
 NK_LIB char *nk_dtoa(char *s, double n);
 #endif
 NK_LIB int nk_text_clamp(const struct nk_user_font *font, const char *text, int text_len, float space, int *glyphs, float *text_width, nk_rune *sep_list, int sep_count);
diff --git a/src/nuklear_math.c b/src/nuklear_math.c
index c24512c2..55e078e9 100644
--- a/src/nuklear_math.c
+++ b/src/nuklear_math.c
@@ -34,8 +34,7 @@
 ///  (it can actually approximate a lot more functions) can be
 ///  found here: www.lolengine.net/wiki/oss/lolremez
 */
-#ifndef NK_INV_SQRT
-#define NK_INV_SQRT nk_inv_sqrt
+#ifdef NK_INV_SQRT_IMPLEMENTATION
 NK_LIB float
 nk_inv_sqrt(float n)
 {
@@ -49,8 +48,7 @@ nk_inv_sqrt(float n)
     return conv.f;
 }
 #endif
-#ifndef NK_SIN
-#define NK_SIN nk_sin
+#ifdef NK_SIN_IMPLEMENTATION
 NK_LIB float
 nk_sin(float x)
 {
@@ -65,8 +63,7 @@ nk_sin(float x)
     return a0 + x*(a1 + x*(a2 + x*(a3 + x*(a4 + x*(a5 + x*(a6 + x*a7))))));
 }
 #endif
-#ifndef NK_COS
-#define NK_COS nk_cos
+#ifdef NK_COS_IMPLEMENTATION
 NK_LIB float
 nk_cos(float x)
 {
@@ -84,8 +81,7 @@ nk_cos(float x)
     return a0 + x*(a1 + x*(a2 + x*(a3 + x*(a4 + x*(a5 + x*(a6 + x*(a7 + x*a8)))))));
 }
 #endif
-#ifndef NK_ATAN
-#define NK_ATAN nk_atan
+#ifdef NK_ATAN_IMPLEMENTATION
 NK_LIB float
 nk_atan(float x)
 {
@@ -104,8 +100,7 @@ nk_atan(float x)
     return u;
 }
 #endif
-#ifndef NK_ATAN2
-#define NK_ATAN2 nk_atan2
+#ifdef NK_ATAN2_IMPLEMENTATION
 NK_LIB float
 nk_atan2(float y, float x)
 {
diff --git a/src/nuklear_property.c b/src/nuklear_property.c
index 668b78c8..6f9eff69 100644
--- a/src/nuklear_property.c
+++ b/src/nuklear_property.c
@@ -282,7 +282,7 @@ nk_do_property(nk_flags *ws,
             break;
         case NK_PROPERTY_DOUBLE:
             nk_string_float_limit(buffer, NK_MAX_FLOAT_PRECISION);
-            variant->value.d = nk_strtod(buffer, 0);
+            variant->value.d = NK_STRTOD(buffer, 0);
             variant->value.d = NK_CLAMP(variant->min_value.d, variant->value.d, variant->max_value.d);
             break;
         }
diff --git a/src/nuklear_util.c b/src/nuklear_util.c
index b55602b1..16e2b649 100644
--- a/src/nuklear_util.c
+++ b/src/nuklear_util.c
@@ -13,8 +13,7 @@ NK_LIB nk_bool nk_is_upper(int c){return (c >= 'A' && c <= 'Z') || (c >= 0xC0 &&
 NK_LIB int nk_to_upper(int c) {return (c >= 'a' && c <= 'z') ? (c - ('a' - 'A')) : c;}
 NK_LIB int nk_to_lower(int c) {return (c >= 'A' && c <= 'Z') ? (c - ('a' + 'A')) : c;}
 
-#ifndef NK_MEMCPY
-#define NK_MEMCPY nk_memcopy
+#ifdef NK_MEMCPY_IMPLEMENTATION
 NK_LIB void*
 nk_memcopy(void *dst0, const void *src0, nk_size length)
 {
@@ -72,8 +71,7 @@ nk_memcopy(void *dst0, const void *src0, nk_size length)
     return (dst0);
 }
 #endif
-#ifndef NK_MEMSET
-#define NK_MEMSET nk_memset
+#ifdef NK_MEMSET_IMPLEMENTATION
 NK_LIB void
 nk_memset(void *ptr, int c0, nk_size size)
 {
@@ -164,6 +162,7 @@ nk_strtoi(const char *str, char **endptr)
         *endptr = (char *)p;
     return neg*value;
 }
+#ifdef NK_STRTOD_IMPLEMENTATION
 NK_API double
 nk_strtod(const char *str, char **endptr)
 {
@@ -221,6 +220,7 @@ nk_strtod(const char *str, char **endptr)
         *endptr = p;
     return number;
 }
+#endif
 NK_API float
 nk_strtof(const char *str, char **endptr)
 {
@@ -499,8 +499,7 @@ nk_itoa(char *s, long n)
     nk_strrev_ascii(s);
     return s;
 }
-#ifndef NK_DTOA
-#define NK_DTOA nk_dtoa
+#ifdef NK_DTOA_IMPLEMENTATION
 NK_LIB char*
 nk_dtoa(char *s, double n)
 {