diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5411cab742..ec1de6d0f8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1167,8 +1167,8 @@ if(SDL_LIBC)
     foreach(_FN
               atan atan2 atanf atan2f ceil ceilf copysign copysignf cos cosf
               exp expf fabs fabsf floor floorf fmod fmodf log logf log10 log10f
-              lround lroundf pow powf round roundf scalbn scalbnf sin sinf sqrt
-              sqrtf tan tanf acos acosf asin asinf trunc truncf)
+              lround lroundf modf modff pow powf round roundf scalbn scalbnf
+              sin sinf sqrt sqrtf tan tanf acos acosf asin asinf trunc truncf)
         string(TOUPPER ${_FN} _UPPER)
         set(LIBC_HASVAR "LIBC_HAS_${_UPPER}")
         check_symbol_exists("${_FN}" "math.h" ${LIBC_HASVAR})
diff --git a/include/build_config/SDL_build_config_android.h b/include/build_config/SDL_build_config_android.h
index 611205573c..1f8c3ef8f2 100644
--- a/include/build_config/SDL_build_config_android.h
+++ b/include/build_config/SDL_build_config_android.h
@@ -121,6 +121,7 @@
 #define HAVE_LROUND 1
 #define HAVE_LROUNDF 1
 #define HAVE_MODF   1
+#define HAVE_MODFF  1
 #define HAVE_POW    1
 #define HAVE_POWF   1
 #define HAVE_ROUND  1
diff --git a/include/build_config/SDL_build_config_ios.h b/include/build_config/SDL_build_config_ios.h
index a523a0883c..6e480a0054 100644
--- a/include/build_config/SDL_build_config_ios.h
+++ b/include/build_config/SDL_build_config_ios.h
@@ -115,6 +115,7 @@
 #define HAVE_LROUND 1
 #define HAVE_LROUNDF 1
 #define HAVE_MODF   1
+#define HAVE_MODFF  1
 #define HAVE_POW    1
 #define HAVE_POWF   1
 #define HAVE_ROUND  1
diff --git a/include/build_config/SDL_build_config_macos.h b/include/build_config/SDL_build_config_macos.h
index 139cd72289..ed3f83a645 100644
--- a/include/build_config/SDL_build_config_macos.h
+++ b/include/build_config/SDL_build_config_macos.h
@@ -117,6 +117,7 @@
 #define HAVE_LROUND 1
 #define HAVE_LROUNDF 1
 #define HAVE_MODF   1
+#define HAVE_MODFF  1
 #define HAVE_POW    1
 #define HAVE_POWF   1
 #define HAVE_ROUND  1
diff --git a/include/build_config/SDL_build_config_winrt.h b/include/build_config/SDL_build_config_winrt.h
index 8623b6e9b8..73d4671459 100644
--- a/include/build_config/SDL_build_config_winrt.h
+++ b/include/build_config/SDL_build_config_winrt.h
@@ -135,6 +135,7 @@
 #define HAVE_LROUND 1
 #define HAVE_LROUNDF 1
 #define HAVE_MODF   1
+#define HAVE_MODFF  1
 #define HAVE_POW    1
 #define HAVE_POWF   1
 #define HAVE_ROUND 1