diff --git a/src/block-components/image/editor.scss b/src/block-components/image/editor.scss
index 32c4acfca..36388ad96 100644
--- a/src/block-components/image/editor.scss
+++ b/src/block-components/image/editor.scss
@@ -245,6 +245,10 @@
 	// Firefox doesn't stretch SVG masks via attributes, stretching is done here. Fixes #246.
 	&.stk-image--shape-stretch .stk-img-resizer-wrapper {
 		mask-size: 100% 100%;
+		// Firefox doesn't automatically inherit the mask-size from the parent. Fixes #3042.
+		img {
+			mask-size: inherit !important;
+		}
 	}
 }
 
diff --git a/src/block-components/image/style.scss b/src/block-components/image/style.scss
index f2038ced8..9499c4093 100644
--- a/src/block-components/image/style.scss
+++ b/src/block-components/image/style.scss
@@ -56,6 +56,10 @@
 		&::before {
 			mask-size: 100% 100%;
 		}
+		// Firefox doesn't automatically inherit the mask-size from the parent. Fixes #3042.
+		img {
+			mask-size: inherit !important;
+		}
 	}
 }