diff --git a/completions/ccache b/completions/ccache
index 63f5a1c6..611a1972 100644
--- a/completions/ccache
+++ b/completions/ccache
@@ -14,6 +14,14 @@ _ccache()
         -h|--help|-V|--version|-F|--max-files|-M|--max-size)
             return
             ;;
+        -o|--set-config)
+            if [[ $cur != *=* ]]; then
+                COMPREPLY=( $( compgen -S = -W "$( $1 -p 2>/dev/null | \
+                    awk '$3 = "=" { print $2 }' )" -- "$cur" ) )
+                [[ $COMPREPLY == *= ]] && compopt -o nospace
+            fi
+            return
+            ;;
     esac
 
     $split && return