diff --git a/share/completions/rustc.fish b/share/completions/rustc.fish
index 27cb6498e..17dc499a5 100644
--- a/share/completions/rustc.fish
+++ b/share/completions/rustc.fish
@@ -33,7 +33,7 @@ for line in $rust_docs
     set docs (string split -m 1 ' ' $line)
     set flag (string replace -r '^([a-z\-]+\=|[a-z\-]+)(.*)' '$1' \
                                 $docs[1])
-    complete -c rustc -x -s C -l codegen -a "$flag" -d "$docs[2]"
+    complete -c rustc -x -s C -l codegen -a (string escape -- "$flag") -d "$docs[2]"
 end
 
 # rustc -Z is only available with the nightly toolchain, which may not be installed
@@ -47,7 +47,7 @@ if rustc +nightly >/dev/null 2>&1
         set docs (string split -m 1 ' ' $line)
         set flag (string replace -r '^([a-z\-]+\=|[a-z\-]+)(.*)' '$1' \
                                        $docs[1])
-        complete -c rustc -x -s Z -a "$flag" -d "$docs[2]"
+        complete -c rustc -x -s Z -a (string escape -- "$flag") -d "$docs[2]"
     end
 end
 
@@ -62,10 +62,10 @@ set -l rust_docs (rustc -W help  \
 
 for line in $rust_docs
     set docs (string split -m 1 ' ' $line)
-    complete -c rustc -x -s W -l warn -a "$docs[1]" -d "$docs[2]"
-    complete -c rustc -x -s A -l allow -a "$docs[1]" -d "$docs[2]"
-    complete -c rustc -x -s D -l deny -a "$docs[1]" -d "$docs[2]"
-    complete -c rustc -x -s F -l forbid -a "$docs[1]" -d "$docs[2]"
+    complete -c rustc -x -s W -l warn -a (string escape -- "$docs[1]") -d "$docs[2]"
+    complete -c rustc -x -s A -l allow -a (string escape -- "$docs[1]") -d "$docs[2]"
+    complete -c rustc -x -s D -l deny -a (string escape -- "$docs[1]") -d "$docs[2]"
+    complete -c rustc -x -s F -l forbid -a (string escape -- "$docs[1]") -d "$docs[2]"
 end
 
 set -e rust_codegen