diff --git a/crates/ide/src/syntax_highlighting/highlight.rs b/crates/ide/src/syntax_highlighting/highlight.rs
index 819d6784a5..a8e93c39f8 100644
--- a/crates/ide/src/syntax_highlighting/highlight.rs
+++ b/crates/ide/src/syntax_highlighting/highlight.rs
@@ -55,7 +55,6 @@ pub(super) fn element(
                 name_ref,
             )
         }
-
         // Simple token-based highlighting
         COMMENT => {
             let comment = element.into_token().and_then(ast::Comment::cast)?;
@@ -132,16 +131,18 @@ pub(super) fn element(
                 .into()
             }
             _ if parent_matches::<ast::PrefixExpr>(&element) => HlOperator::Other.into(),
-            T![+] | T![-] | T![*] | T![/] | T![+=] | T![-=] | T![*=] | T![/=]
-                if parent_matches::<ast::BinExpr>(&element) =>
-            {
+            T![+] | T![-] | T![*] | T![/] if parent_matches::<ast::BinExpr>(&element) => {
                 HlOperator::Arithmetic.into()
             }
-            T![|] | T![&] | T![!] | T![^] | T![|=] | T![&=] | T![^=]
-                if parent_matches::<ast::BinExpr>(&element) =>
-            {
+            T![+=] | T![-=] | T![*=] | T![/=] if parent_matches::<ast::BinExpr>(&element) => {
+                Highlight::from(HlOperator::Arithmetic) | HlMod::Mutable
+            }
+            T![|] | T![&] | T![!] | T![^] if parent_matches::<ast::BinExpr>(&element) => {
                 HlOperator::Bitwise.into()
             }
+            T![|=] | T![&=] | T![^=] if parent_matches::<ast::BinExpr>(&element) => {
+                Highlight::from(HlOperator::Bitwise) | HlMod::Mutable
+            }
             T![&&] | T![||] if parent_matches::<ast::BinExpr>(&element) => {
                 HlOperator::Logical.into()
             }
diff --git a/crates/ide/src/syntax_highlighting/test_data/highlighting.html b/crates/ide/src/syntax_highlighting/test_data/highlighting.html
index 96969a7bb3..04148767d0 100644
--- a/crates/ide/src/syntax_highlighting/test_data/highlighting.html
+++ b/crates/ide/src/syntax_highlighting/test_data/highlighting.html
@@ -195,6 +195,7 @@ pre                 { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padd
     <span class="macro">noop!</span><span class="parenthesis">(</span><span class="macro">noop</span><span class="macro">!</span><span class="parenthesis">(</span><span class="numeric_literal">1</span><span class="parenthesis">)</span><span class="parenthesis">)</span><span class="semicolon">;</span>
 
     <span class="keyword">let</span> <span class="keyword">mut</span> <span class="variable declaration mutable">x</span> <span class="operator">=</span> <span class="numeric_literal">42</span><span class="semicolon">;</span>
+    <span class="variable mutable">x</span> <span class="arithmetic mutable">+=</span> <span class="numeric_literal">1</span><span class="semicolon">;</span>
     <span class="keyword">let</span> <span class="variable declaration mutable">y</span> <span class="operator">=</span> <span class="operator">&</span><span class="keyword">mut</span> <span class="variable mutable">x</span><span class="semicolon">;</span>
     <span class="keyword">let</span> <span class="variable declaration">z</span> <span class="operator">=</span> <span class="operator">&</span><span class="variable mutable">y</span><span class="semicolon">;</span>
 
diff --git a/crates/ide/src/syntax_highlighting/tests.rs b/crates/ide/src/syntax_highlighting/tests.rs
index 81a98a606e..740127202f 100644
--- a/crates/ide/src/syntax_highlighting/tests.rs
+++ b/crates/ide/src/syntax_highlighting/tests.rs
@@ -168,6 +168,7 @@ fn main() {
     noop!(noop!(1));
 
     let mut x = 42;
+    x += 1;
     let y = &mut x;
     let z = &y;