diff --git a/gitprompt.sh b/gitprompt.sh
index 78f4de80..b85da609 100755
--- a/gitprompt.sh
+++ b/gitprompt.sh
@@ -346,7 +346,13 @@ function setGitPrompt() {
   unset GIT_PROMPT_SHOW_UNTRACKED_FILES
 
   if [[ -e "$repo/.bash-git-rc" ]]; then
-    source "$repo/.bash-git-rc"
+    # The config file can only contain variable declarations on the form A_B=0 or G_P=all
+    local CONFIG_SYNTAX="^(FETCH_REMOTE_STATUS|GIT_PROMPT_SHOW_UNTRACKED_FILES|GIT_PROMPT_IGNORE)=[0-9a-z]+$"
+    if egrep -q -v "$CONFIG_SYNTAX" "$repo/.bash-git-rc"; then
+      echo ".bash-git-rc can only contain variable values on the form NAME=value. Ignoring file." >&2
+    else
+      source "$repo/.bash-git-rc"
+    fi
   fi
 
   if [ -z "${GIT_PROMPT_SHOW_UNTRACKED_FILES}" ]; then