diff --git a/src/material-experimental/mdc-button/fab.scss b/src/material-experimental/mdc-button/fab.scss
index 6add119bb32a..b93fe1dbcdf5 100644
--- a/src/material-experimental/mdc-button/fab.scss
+++ b/src/material-experimental/mdc-button/fab.scss
@@ -11,6 +11,9 @@
   @include button-base.mat-private-button-touch-target(true);
   @include private.private-animation-noop();
 
+  // Prevent the button from shrinking since it's always supposed to be a circle.
+  flex-shrink: 0;
+
   // MDC adds some styles to fab and mini-fab that conflict with some of our focus indicator
   // styles and don't actually do anything. This undoes those conflicting styles.
   &:not(.mdc-ripple-upgraded):focus::before {
diff --git a/src/material-experimental/mdc-button/icon-button.scss b/src/material-experimental/mdc-button/icon-button.scss
index 93d75f836c0a..379c22de9356 100644
--- a/src/material-experimental/mdc-button/icon-button.scss
+++ b/src/material-experimental/mdc-button/icon-button.scss
@@ -15,6 +15,9 @@
   // Border radius is inherited by ripple to know its shape. Set to 50% so the ripple is round.
   border-radius: 50%;
 
+  // Prevent the button from shrinking since it's always supposed to be a circle.
+  flex-shrink: 0;
+
   @include button-base.mat-private-button-disabled();
   @include button-base.mat-private-button-touch-target(true);
   @include private.private-animation-noop();