diff --git a/RegExpSupport/src/org/intellij/lang/regexp/validation/RegExpAnnotator.java b/RegExpSupport/src/org/intellij/lang/regexp/validation/RegExpAnnotator.java
index 1d32bf8ab6eb..d326d2c28557 100644
--- a/RegExpSupport/src/org/intellij/lang/regexp/validation/RegExpAnnotator.java
+++ b/RegExpSupport/src/org/intellij/lang/regexp/validation/RegExpAnnotator.java
@@ -124,14 +124,14 @@ public final class RegExpAnnotator extends RegExpElementVisitor implements Annot
   public void visitRegExpBackref(final RegExpBackref backref) {
     final RegExpGroup group = backref.resolve();
     if (group == null) {
-      final Annotation a = myHolder.createErrorAnnotation(backref, "Unresolved backreference");
+      final Annotation a = myHolder.createErrorAnnotation(backref, "Unresolved back reference");
       if (a != null) {
         // IDEA-9381
         a.setHighlightType(ProblemHighlightType.LIKE_UNKNOWN_SYMBOL);
       }
     }
     else if (PsiTreeUtil.isAncestor(group, backref, true)) {
-      myHolder.createWarningAnnotation(backref, "Backreference is nested into the capturing group it refers to");
+      myHolder.createWarningAnnotation(backref, "Back reference is nested into the capturing group it refers to");
     }
   }
 
@@ -173,7 +173,7 @@ public final class RegExpAnnotator extends RegExpElementVisitor implements Annot
     */
     final RegExpGroup group = groupRef.resolve();
     if (group == null) {
-      final Annotation a = myHolder.createErrorAnnotation(groupRef, "Unresolved backreference");
+      final Annotation a = myHolder.createErrorAnnotation(groupRef, "Unresolved back reference");
       if (a != null) {
         // IDEA-9381
         a.setHighlightType(ProblemHighlightType.LIKE_UNKNOWN_SYMBOL);