diff --git a/frontends/verilog/verilog_lexer.l b/frontends/verilog/verilog_lexer.l
index e6fa6361e..028106381 100644
--- a/frontends/verilog/verilog_lexer.l
+++ b/frontends/verilog/verilog_lexer.l
@@ -526,6 +526,12 @@ import[ \t\r\n]+\"(DPI|DPI-C)\"[ \t\r\n]+function[ \t\r\n]+ {
 
 ".*" { return TOK_WILDCARD_CONNECT; }
 
+"|=" { SV_KEYWORD(TOK_OR_ASSIGN); }
+"&=" { SV_KEYWORD(TOK_AND_ASSIGN); }
+"+=" { SV_KEYWORD(TOK_PLUS_ASSIGN); }
+"-=" { SV_KEYWORD(TOK_SUB_ASSIGN); }
+"^=" { SV_KEYWORD(TOK_XOR_ASSIGN); }
+
 [-+]?[=*]> {
 	if (!specify_mode) REJECT;
 	yylval->string = new std::string(yytext);
diff --git a/frontends/verilog/verilog_parser.y b/frontends/verilog/verilog_parser.y
index 4f3df575b..96d9299fe 100644
--- a/frontends/verilog/verilog_parser.y
+++ b/frontends/verilog/verilog_parser.y
@@ -256,7 +256,7 @@ static void rewriteAsMemoryNode(AstNode *node, AstNode *rangeNode)
 %token TOK_PACKAGE TOK_ENDPACKAGE TOK_PACKAGESEP
 %token TOK_INTERFACE TOK_ENDINTERFACE TOK_MODPORT TOK_VAR TOK_WILDCARD_CONNECT
 %token TOK_INPUT TOK_OUTPUT TOK_INOUT TOK_WIRE TOK_WAND TOK_WOR TOK_REG TOK_LOGIC
-%token TOK_INTEGER TOK_SIGNED TOK_ASSIGN TOK_ALWAYS TOK_INITIAL
+%token TOK_INTEGER TOK_SIGNED TOK_ASSIGN TOK_PLUS_ASSIGN TOK_ALWAYS TOK_INITIAL
 %token TOK_ALWAYS_FF TOK_ALWAYS_COMB TOK_ALWAYS_LATCH
 %token TOK_BEGIN TOK_END TOK_IF TOK_ELSE TOK_FOR TOK_WHILE TOK_REPEAT
 %token TOK_DPI_FUNCTION TOK_POSEDGE TOK_NEGEDGE TOK_OR TOK_AUTOMATIC
@@ -269,7 +269,8 @@ static void rewriteAsMemoryNode(AstNode *node, AstNode *rangeNode)
 %token TOK_POS_INDEXED TOK_NEG_INDEXED TOK_PROPERTY TOK_ENUM TOK_TYPEDEF
 %token TOK_RAND TOK_CONST TOK_CHECKER TOK_ENDCHECKER TOK_EVENTUALLY
 %token TOK_INCREMENT TOK_DECREMENT TOK_UNIQUE TOK_PRIORITY
-%token TOK_STRUCT TOK_PACKED TOK_UNSIGNED TOK_INT TOK_BYTE TOK_SHORTINT TOK_UNION 
+%token TOK_STRUCT TOK_PACKED TOK_UNSIGNED TOK_INT TOK_BYTE TOK_SHORTINT TOK_UNION
+%token TOK_OR_ASSIGN TOK_XOR_ASSIGN TOK_AND_ASSIGN TOK_SUB_ASSIGN
 
 %type <ast> range range_or_multirange  non_opt_range non_opt_multirange range_or_signed_int
 %type <ast> wire_type expr basic_expr concat_list rvalue lvalue lvalue_concat_list
@@ -2334,6 +2335,46 @@ simple_behavioral_stmt:
 		ast_stack.back()->children.push_back(node);
 		SET_AST_NODE_LOC(node, @2, @5);
 		append_attr(node, $1);
+	} |
+	attr lvalue TOK_XOR_ASSIGN delay expr {
+		AstNode *xor_node = new AstNode(AST_BIT_XOR, $2->clone(), $5);
+		AstNode *node = new AstNode(AST_ASSIGN_EQ, $2, xor_node);
+		SET_AST_NODE_LOC(xor_node, @2, @5);
+		SET_AST_NODE_LOC(node, @2, @5);
+		ast_stack.back()->children.push_back(node);
+		append_attr(node, $1);
+	} |
+	attr lvalue TOK_OR_ASSIGN delay expr {
+		AstNode *or_node = new AstNode(AST_BIT_OR, $2->clone(), $5);
+		SET_AST_NODE_LOC(or_node, @2, @5);
+		AstNode *node = new AstNode(AST_ASSIGN_EQ, $2, or_node);
+		SET_AST_NODE_LOC(node, @2, @5);
+		ast_stack.back()->children.push_back(node);
+		append_attr(node, $1);
+	} |
+	attr lvalue TOK_PLUS_ASSIGN delay expr {
+		AstNode *add_node = new AstNode(AST_ADD, $2->clone(), $5);
+		AstNode *node = new AstNode(AST_ASSIGN_EQ, $2, add_node);
+		SET_AST_NODE_LOC(node, @2, @5);
+		SET_AST_NODE_LOC(add_node, @2, @5);
+		ast_stack.back()->children.push_back(node);
+		append_attr(node, $1);
+	} |
+	attr lvalue TOK_SUB_ASSIGN delay expr {
+		AstNode *sub_node = new AstNode(AST_SUB, $2->clone(), $5);
+		AstNode *node = new AstNode(AST_ASSIGN_EQ, $2, sub_node);
+		SET_AST_NODE_LOC(node, @2, @5);
+		SET_AST_NODE_LOC(sub_node, @2, @5);
+		ast_stack.back()->children.push_back(node);
+		append_attr(node, $1);
+	} |
+	attr lvalue TOK_AND_ASSIGN delay expr {
+		AstNode *and_node = new AstNode(AST_BIT_AND, $2->clone(), $5);
+		AstNode *node = new AstNode(AST_ASSIGN_EQ, $2, and_node);
+		SET_AST_NODE_LOC(node, @2, @5);
+		SET_AST_NODE_LOC(and_node, @2, @5);
+		ast_stack.back()->children.push_back(node);
+		append_attr(node, $1);
 	};
 
 // this production creates the obligatory if-else shift/reduce conflict
diff --git a/tests/opt/opt_expr_combined_assign.ys b/tests/opt/opt_expr_combined_assign.ys
new file mode 100644
index 000000000..b18923c7b
--- /dev/null
+++ b/tests/opt/opt_expr_combined_assign.ys
@@ -0,0 +1,83 @@
+read_verilog -sv <<EOT
+module opt_expr_or_test(input [3:0] i, input [7:0] j, output [8:0] o);
+wire[8:0] a = 8'b0;
+initial begin
+	a |= i;
+	a |= j;
+end
+    assign o = a;
+endmodule
+EOT
+proc
+equiv_opt -assert opt_expr -fine
+design -load postopt
+
+select -assert-count 1 t:$or r:A_WIDTH=4 r:B_WIDTH=4 r:Y_WIDTH=4 %i %i %i
+
+design -reset
+read_verilog -sv <<EOT
+module opt_expr_add_test(input [3:0] i, input [7:0] j, output [8:0] o);
+wire[8:0] a = 8'b0;
+initial begin
+        a += i;
+        a += j;
+end
+    assign o = a;
+endmodule
+EOT
+proc
+equiv_opt -assert opt_expr -fine
+design -load postopt
+
+select -assert-count 1 t:$add r:A_WIDTH=9 r:B_WIDTH=8 r:Y_WIDTH=9 %i %i %i
+
+design -reset
+read_verilog -sv <<EOT
+module opt_expr_xor_test(input [3:0] i, input [7:0] j, output [8:0] o);
+wire[8:0] a = 8'b0;
+initial begin
+        a ^= i;
+        a ^= j;
+end
+    assign o = a;
+endmodule
+EOT
+proc
+equiv_opt -assert opt_expr -fine
+design -load postopt
+
+select -assert-count 1 t:$xor r:A_WIDTH=4 r:B_WIDTH=4 r:Y_WIDTH=4 %i %i %i
+
+design -reset
+read_verilog -sv <<EOT
+module opt_expr_sub_test(input [3:0] i, input [7:0] j, output [8:0] o);
+wire[8:0] a = 8'b0;
+initial begin
+        a -= i;
+        a -= j;
+end
+    assign o = a;
+endmodule
+EOT
+proc
+equiv_opt -assert opt_expr -fine
+design -load postopt
+
+select -assert-count 1 t:$sub r:A_WIDTH=9 r:B_WIDTH=8 r:Y_WIDTH=9 %i %i %i
+
+design -reset
+read_verilog -sv <<EOT
+module opt_expr_and_test(input [3:0] i, input [7:0] j, output [8:0] o);
+wire[8:0] a = 8'b11111111;
+initial begin
+        a &= i;
+        a &= j;
+end
+    assign o = a;
+endmodule
+EOT
+proc
+equiv_opt -assert opt_expr -fine
+design -load postopt
+
+select -assert-count 1 t:$and r:A_WIDTH=4 r:B_WIDTH=4 r:Y_WIDTH=4 %i %i %i