diff --git a/browser/themes/linux/devtools/toolbox.css b/browser/themes/linux/devtools/toolbox.css
index e0a7683b51a8..ed42d821296e 100644
--- a/browser/themes/linux/devtools/toolbox.css
+++ b/browser/themes/linux/devtools/toolbox.css
@@ -150,10 +150,9 @@
 
 .devtools-tab {
   -moz-appearance: none;
-  width: 47px;
-  min-width: 47px;
+  min-width: 32px;
   min-height: 32px;
-  max-width: 137px;
+  max-width: 127px;
   color: #b6babf;
   margin: 0;
   padding: 0;
@@ -168,8 +167,8 @@
 
 .devtools-tab > image {
   border: none;
-  -moz-margin-end: 6px;
-  -moz-margin-start: 16px;
+  -moz-margin-end: 0;
+  -moz-margin-start: 8px;
   opacity: 0.6;
   max-height: 16px;
 }
diff --git a/browser/themes/osx/devtools/toolbox.css b/browser/themes/osx/devtools/toolbox.css
index 4c6524d90a62..cca78b2264b0 100644
--- a/browser/themes/osx/devtools/toolbox.css
+++ b/browser/themes/osx/devtools/toolbox.css
@@ -139,10 +139,9 @@
 
 .devtools-tab {
   -moz-appearance: none;
-  width: 47px;
-  min-width: 47px;
+  min-width: 32px;
   min-height: 32px;
-  max-width: 137px;
+  max-width: 110px;
   color: #b6babf;
   margin: 0;
   padding: 0;
@@ -156,8 +155,8 @@
 }
 
 .devtools-tab > image {
-  -moz-margin-end: 6px;
-  -moz-margin-start: 16px;
+  -moz-margin-end: 0;
+  -moz-margin-start: 8px;
   opacity: 0.6;
 }
 
diff --git a/browser/themes/windows/devtools/toolbox.css b/browser/themes/windows/devtools/toolbox.css
index e1ac3a6430f4..2361d5f196e6 100644
--- a/browser/themes/windows/devtools/toolbox.css
+++ b/browser/themes/windows/devtools/toolbox.css
@@ -151,10 +151,9 @@
 
 .devtools-tab {
   -moz-appearance: none;
-  width: 47px;
-  min-width: 47px;
+  min-width: 32px;
   min-height: 32px;
-  max-width: 137px;
+  max-width: 110px;
   color: #b6babf;
   margin: 0;
   padding: 0;
@@ -169,8 +168,8 @@
 }
 
 .devtools-tab > image {
-  -moz-margin-end: 6px;
-  -moz-margin-start: 16px;
+  -moz-margin-end: 0;
+  -moz-margin-start: 8px;
   opacity: 0.6;
 }