diff --git a/theme/imagecaption/theme.scss b/theme/imagecaption/theme.scss
index f0cdc92d..ea68bc09 100644
--- a/theme/imagecaption/theme.scss
+++ b/theme/imagecaption/theme.scss
@@ -22,6 +22,5 @@
 			@include ck-box-shadow( $ck-inner-shadow );
 			background-color: ck-color( 'background' );;
 		}
-
 	}
 }
diff --git a/theme/theme.scss b/theme/theme.scss
index d5289c64..f6ca039f 100644
--- a/theme/theme.scss
+++ b/theme/theme.scss
@@ -37,4 +37,7 @@
 
 	// Center the image if its width is smaller than content's width.
 	margin: 0 auto;
+
+	// Make sure the image never exceeds the size of the parent container (#67).
+	max-width: 100%;
 }