diff --git a/pkgs/misc/emulators/dolphin-emu/default.nix b/pkgs/misc/emulators/dolphin-emu/default.nix
index bb5b12038f8..db510024241 100644
--- a/pkgs/misc/emulators/dolphin-emu/default.nix
+++ b/pkgs/misc/emulators/dolphin-emu/default.nix
@@ -14,6 +14,11 @@ stdenv.mkDerivation rec {
     sha256 = "07mlfnh0hwvk6xarcg315x7z2j0qbg9g7cm040df9c8psiahc3g6";
   };
 
+  postPatch = ''
+    substituteInPlace Source/Core/VideoBackends/OGL/RasterFont.cpp \
+      --replace " CHAR_WIDTH " " CHARWIDTH "
+  '';
+
   cmakeFlags = ''
     -DGTK2_GLIBCONFIG_INCLUDE_DIR=${glib.out}/lib/glib-2.0/include
     -DGTK2_GDKCONFIG_INCLUDE_DIR=${gtk2.out}/lib/gtk-2.0/include
diff --git a/pkgs/misc/emulators/dolphin-emu/master.nix b/pkgs/misc/emulators/dolphin-emu/master.nix
index 990870d35d6..499e1177c3e 100644
--- a/pkgs/misc/emulators/dolphin-emu/master.nix
+++ b/pkgs/misc/emulators/dolphin-emu/master.nix
@@ -12,6 +12,12 @@ stdenv.mkDerivation rec {
     fetchSubmodules = false;
   };
 
+  postPatch = ''
+    for f in Source/Core/VideoBackends/{Software,OGL}/RasterFont.{h,cpp}; do
+      substituteInPlace "$f" --replace " CHAR_WIDTH " " CHARWIDTH "
+    done
+  '';
+
   cmakeFlags = ''
     -DGTK2_GLIBCONFIG_INCLUDE_DIR=${glib.out}/lib/glib-2.0/include
     -DGTK2_GDKCONFIG_INCLUDE_DIR=${gtk2.out}/lib/gtk-2.0/include