diff --git a/tests/themes/run.sh b/tests/themes/run.sh
index 21c7d1dbf..788403f94 100755
--- a/tests/themes/run.sh
+++ b/tests/themes/run.sh
@@ -12,6 +12,17 @@ if ! [ -f CMakeLists.txt ]; then
 fi
 source_dir="$PWD"
 
+# Either the build dir is passed in $CMAKE_BINARY_DIR or we guess based on $PWD
+# Same as in tests/run.sh.
+build_dir="$CMAKE_BINARY_DIR"
+if [ -z "$build_dir" ]; then
+    if [ -d "$source_dir/build" ]; then
+        build_dir="$source_dir/build"
+    else
+        build_dir="$source_dir"
+    fi
+fi
+
 config_file="$(mktemp)"
 
 # Cleanup on errors / aborting.
@@ -28,7 +39,7 @@ for theme_file in themes/*/theme.lua; do
   sed "s~default/theme~$theme_name/theme~g" "awesomerc.lua" > "$config_file"
 
   AWESOME_RC_FILE="$config_file" \
-    AWESOME_THEMES_PATH="$source_dir/themes" \
+    AWESOME_THEMES_PATH="$build_dir/themes" \
     AWESOME_ICON_PATH="$PWD/icons" \
     "$source_dir/tests/run.sh" themes/tests.lua
 done