diff --git a/.travis.yml b/.travis.yml
index b4e3e920..373dcf42 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -126,7 +126,7 @@ before_script:
       if [ "$BUILD_SYSTEM" == "cmake" ]; then
         # Make build directory and generate CMake build files
         mkdir -p ${CMAKE_BUILD_DIR} && cd ${CMAKE_BUILD_DIR}
-        cmake .. -DCMAKE_BUILD_TYPE=Release -DFIX_BUGS=ON -DRENDERER=$RENDERER -DCMAKE_CXX_FLAGS="-Wall -Wextra -pedantic"
+        cmake .. -DCMAKE_BUILD_TYPE=Release -DFIX_BUGS=ON -DRENDERER=$RENDERER -DCMAKE_C_FLAGS="-Wall -Wextra -pedantic" -DCMAKE_CXX_FLAGS="-Wall -Wextra -pedantic"
         cd ..
       fi
 
@@ -139,7 +139,7 @@ script:
         cd ..
       else
         # Make build
-        make -j $JOBS FIX_BUGS=1 RELEASE=1 RENDERER=$RENDERER CXXFLAGS="-Wall -Wextra -pedantic"
+        make -j $JOBS FIX_BUGS=1 RELEASE=1 RENDERER=$RENDERER CFLAGS="-Wall -Wextra -pedantic" CXXFLAGS="-Wall -Wextra -pedantic"
       fi
 
 after_success:
diff --git a/README.md b/README.md
index 923db0bd..411105c2 100644
--- a/README.md
+++ b/README.md
@@ -108,7 +108,7 @@ Name | Function
 `STATIC=1` | Produce a statically-linked executable (good for Windows builds, so you don't need to bundle DLL files)
 `WINDOWS=1` | Build for Windows
 
-You can pass your own compiler flags by defining `CXXFLAGS`.
+You can pass your own compiler flags by defining `CFLAGS` and `CXXFLAGS`.
 
 Once built, the executables can be found in the `game_english`/`game_japanese` folder, depending on the selected language.