diff --git a/src/SFML/Audio/SoundFile.cpp b/src/SFML/Audio/SoundFile.cpp
index 2031d90d..67bc6ca2 100644
--- a/src/SFML/Audio/SoundFile.cpp
+++ b/src/SFML/Audio/SoundFile.cpp
@@ -286,34 +286,34 @@ int SoundFile::getFormatFromFilename(const std::string& filename)
     std::string ext = "wav";
     std::string::size_type pos = filename.find_last_of(".");
     if (pos != std::string::npos)
-        ext = filename.substr(pos + 1);
+        ext = toLower(filename.substr(pos + 1));
 
     // Match every supported extension with its format constant
-    if (toLower(ext) == "wav"  ) return SF_FORMAT_WAV;
-    if (toLower(ext) == "aif"  ) return SF_FORMAT_AIFF;
-    if (toLower(ext) == "aiff" ) return SF_FORMAT_AIFF;
-    if (toLower(ext) == "au"   ) return SF_FORMAT_AU;
-    if (toLower(ext) == "raw"  ) return SF_FORMAT_RAW;
-    if (toLower(ext) == "paf"  ) return SF_FORMAT_PAF;
-    if (toLower(ext) == "svx"  ) return SF_FORMAT_SVX;
-    if (toLower(ext) == "nist" ) return SF_FORMAT_NIST;
-    if (toLower(ext) == "voc"  ) return SF_FORMAT_VOC;
-    if (toLower(ext) == "sf"   ) return SF_FORMAT_IRCAM;
-    if (toLower(ext) == "w64"  ) return SF_FORMAT_W64;
-    if (toLower(ext) == "mat4" ) return SF_FORMAT_MAT4;
-    if (toLower(ext) == "mat5" ) return SF_FORMAT_MAT5;
-    if (toLower(ext) == "pvf"  ) return SF_FORMAT_PVF;
-    if (toLower(ext) == "xi"   ) return SF_FORMAT_XI;
-    if (toLower(ext) == "htk"  ) return SF_FORMAT_HTK;
-    if (toLower(ext) == "sds"  ) return SF_FORMAT_SDS;
-    if (toLower(ext) == "avr"  ) return SF_FORMAT_AVR;
-    if (toLower(ext) == "sd2"  ) return SF_FORMAT_SD2;
-    if (toLower(ext) == "flac" ) return SF_FORMAT_FLAC;
-    if (toLower(ext) == "caf"  ) return SF_FORMAT_CAF;
-    if (toLower(ext) == "wve"  ) return SF_FORMAT_WVE;
-    if (toLower(ext) == "ogg"  ) return SF_FORMAT_OGG;
-    if (toLower(ext) == "mpc2k") return SF_FORMAT_MPC2K;
-    if (toLower(ext) == "rf64" ) return SF_FORMAT_RF64;
+    if (ext == "wav"  ) return SF_FORMAT_WAV;
+    if (ext == "aif"  ) return SF_FORMAT_AIFF;
+    if (ext == "aiff" ) return SF_FORMAT_AIFF;
+    if (ext == "au"   ) return SF_FORMAT_AU;
+    if (ext == "raw"  ) return SF_FORMAT_RAW;
+    if (ext == "paf"  ) return SF_FORMAT_PAF;
+    if (ext == "svx"  ) return SF_FORMAT_SVX;
+    if (ext == "nist" ) return SF_FORMAT_NIST;
+    if (ext == "voc"  ) return SF_FORMAT_VOC;
+    if (ext == "sf"   ) return SF_FORMAT_IRCAM;
+    if (ext == "w64"  ) return SF_FORMAT_W64;
+    if (ext == "mat4" ) return SF_FORMAT_MAT4;
+    if (ext == "mat5" ) return SF_FORMAT_MAT5;
+    if (ext == "pvf"  ) return SF_FORMAT_PVF;
+    if (ext == "xi"   ) return SF_FORMAT_XI;
+    if (ext == "htk"  ) return SF_FORMAT_HTK;
+    if (ext == "sds"  ) return SF_FORMAT_SDS;
+    if (ext == "avr"  ) return SF_FORMAT_AVR;
+    if (ext == "sd2"  ) return SF_FORMAT_SD2;
+    if (ext == "flac" ) return SF_FORMAT_FLAC;
+    if (ext == "caf"  ) return SF_FORMAT_CAF;
+    if (ext == "wve"  ) return SF_FORMAT_WVE;
+    if (ext == "ogg"  ) return SF_FORMAT_OGG;
+    if (ext == "mpc2k") return SF_FORMAT_MPC2K;
+    if (ext == "rf64" ) return SF_FORMAT_RF64;
 
     return -1;
 }
diff --git a/src/SFML/Graphics/ImageLoader.cpp b/src/SFML/Graphics/ImageLoader.cpp
index 985ce0f1..c9e5cb5b 100644
--- a/src/SFML/Graphics/ImageLoader.cpp
+++ b/src/SFML/Graphics/ImageLoader.cpp
@@ -229,27 +229,27 @@ bool ImageLoader::saveImageToFile(const std::string& filename, const std::vector
         if (filename.size() > 3)
         {
             // Extract the extension
-            std::string extension = filename.substr(filename.size() - 3);
+            std::string extension = toLower(filename.substr(filename.size() - 3));
 
-            if (toLower(extension) == "bmp")
+            if (extension == "bmp")
             {
                 // BMP format
                 if (stbi_write_bmp(filename.c_str(), size.x, size.y, 4, &pixels[0]))
                     return true;
             }
-            else if (toLower(extension) == "tga")
+            else if (extension == "tga")
             {
                 // TGA format
                 if (stbi_write_tga(filename.c_str(), size.x, size.y, 4, &pixels[0]))
                     return true;
             }
-            else if(toLower(extension) == "png")
+            else if (extension == "png")
             {
                 // PNG format
                 if (stbi_write_png(filename.c_str(), size.x, size.y, 4, &pixels[0], 0))
                     return true;
             }
-            else if (toLower(extension) == "jpg")
+            else if (extension == "jpg")
             {
                 // JPG format
                 if (writeJpg(filename, pixels, size.x, size.y))