diff --git a/components/prism-asmatmel.js b/components/prism-asmatmel.js
index b24883c666..53b52e3853 100644
--- a/components/prism-asmatmel.js
+++ b/components/prism-asmatmel.js
@@ -38,6 +38,6 @@ Prism.languages.asmatmel = {
 		pattern: /\b[acznvshtixy]\b/i,
 		alias: 'variable'
 	},
-	'operator': />>=?|<<=?|&&?|\|\|?|[-+*/%&|^!=<>?]=?/,
+	'operator': />>=?|<<=?|&[&=]?|\|[\|=]?|[-+*/%^!=<>?]=?/,
 	'punctuation': /[(),:]/
 };
diff --git a/components/prism-asmatmel.min.js b/components/prism-asmatmel.min.js
index 6e6f8c6912..8c021f9ead 100644
--- a/components/prism-asmatmel.min.js
+++ b/components/prism-asmatmel.min.js
@@ -1 +1 @@
-Prism.languages.asmatmel={comment:{pattern:/;.*/,greedy:!0},string:{pattern:/(["'`])(?:\\.|(?!\1)[^\\\r\n])*\1/,greedy:!0},constant:/\b(?:PORT[A-Z]|DDR[A-Z]|(?:DD|P)[A-Z](?:\d|[0-2]\d|3[01]))\b/,directive:{pattern:/\.\w+(?= )/,alias:"property"},"r-register":{pattern:/\br(?:\d|[12]\d|3[01])\b/,alias:"variable"},"op-code":{pattern:/\b(?:ADC|ADD|ADIW|AND|ANDI|ASR|BCLR|BLD|BRBC|BRBS|BRCC|BRCS|BREAK|BREQ|BRGE|BRHC|BRHS|BRID|BRIE|BRLO|BRLT|BRMI|BRNE|BRPL|BRSH|BRTC|BRTS|BRVC|BRVS|BSET|BST|CALL|CBI|CBR|CLC|CLH|CLI|CLN|CLR|CLS|CLT|CLV|CLZ|COM|CP|CPC|CPI|CPSE|DEC|DES|EICALL|EIJMP|ELPM|EOR|FMUL|FMULS|FMULSU|ICALL|IJMP|IN|INC|JMP|LAC|LAS|LAT|LD|LD[A-Za-z0-9]|LPM|LSL|LSR|MOV|MOVW|MUL|MULS|MULSU|NEG|NOP|OR|ORI|OUT|POP|PUSH|RCALL|RET|RETI|RJMP|ROL|ROR|SBC|SBCI|SBI|SBIC|SBIS|SBIW|SBR|SBRC|SBRS|SEC|SEH|SEI|SEN|SER|SES|SET|SEV|SEZ|SLEEP|SPM|ST|ST[A-Z0-9]|SUB|SUBI|SWAP|TST|WDR|XCH|adc|add|adiw|and|andi|asr|bclr|bld|brbc|brbs|brcc|brcs|break|breq|brge|brhc|brhs|brid|brie|brlo|brlt|brmi|brne|brpl|brsh|brtc|brts|brvc|brvs|bset|bst|call|cbi|cbr|clc|clh|cli|cln|clr|cls|clt|clv|clz|com|cp|cpc|cpi|cpse|dec|des|eicall|eijmp|elpm|eor|fmul|fmuls|fmulsu|icall|ijmp|in|inc|jmp|lac|las|lat|ld|ld[a-z0-9]|lpm|lsl|lsr|mov|movw|mul|muls|mulsu|neg|nop|or|ori|out|pop|push|rcall|ret|reti|rjmp|rol|ror|sbc|sbci|sbi|sbic|sbis|sbiw|sbr|sbrc|sbrs|sec|seh|sei|sen|ser|ses|set|sev|sez|sleep|spm|st|st[a-zA-Z0-9]|sub|subi|swap|tst|wdr|xch)\b/,alias:"keyword"},"hex-number":{pattern:/#?\$[\da-f]{2,4}\b/i,alias:"number"},"binary-number":{pattern:/#?%[01]+\b/,alias:"number"},"decimal-number":{pattern:/#?\b\d+\b/,alias:"number"},register:{pattern:/\b[acznvshtixy]\b/i,alias:"variable"},operator:/>>=?|<<=?|&&?|\|\|?|[-+*/%&|^!=<>?]=?/,punctuation:/[(),:]/};
\ No newline at end of file
+Prism.languages.asmatmel={comment:{pattern:/;.*/,greedy:!0},string:{pattern:/(["'`])(?:\\.|(?!\1)[^\\\r\n])*\1/,greedy:!0},constant:/\b(?:PORT[A-Z]|DDR[A-Z]|(?:DD|P)[A-Z](?:\d|[0-2]\d|3[01]))\b/,directive:{pattern:/\.\w+(?= )/,alias:"property"},"r-register":{pattern:/\br(?:\d|[12]\d|3[01])\b/,alias:"variable"},"op-code":{pattern:/\b(?:ADC|ADD|ADIW|AND|ANDI|ASR|BCLR|BLD|BRBC|BRBS|BRCC|BRCS|BREAK|BREQ|BRGE|BRHC|BRHS|BRID|BRIE|BRLO|BRLT|BRMI|BRNE|BRPL|BRSH|BRTC|BRTS|BRVC|BRVS|BSET|BST|CALL|CBI|CBR|CLC|CLH|CLI|CLN|CLR|CLS|CLT|CLV|CLZ|COM|CP|CPC|CPI|CPSE|DEC|DES|EICALL|EIJMP|ELPM|EOR|FMUL|FMULS|FMULSU|ICALL|IJMP|IN|INC|JMP|LAC|LAS|LAT|LD|LD[A-Za-z0-9]|LPM|LSL|LSR|MOV|MOVW|MUL|MULS|MULSU|NEG|NOP|OR|ORI|OUT|POP|PUSH|RCALL|RET|RETI|RJMP|ROL|ROR|SBC|SBCI|SBI|SBIC|SBIS|SBIW|SBR|SBRC|SBRS|SEC|SEH|SEI|SEN|SER|SES|SET|SEV|SEZ|SLEEP|SPM|ST|ST[A-Z0-9]|SUB|SUBI|SWAP|TST|WDR|XCH|adc|add|adiw|and|andi|asr|bclr|bld|brbc|brbs|brcc|brcs|break|breq|brge|brhc|brhs|brid|brie|brlo|brlt|brmi|brne|brpl|brsh|brtc|brts|brvc|brvs|bset|bst|call|cbi|cbr|clc|clh|cli|cln|clr|cls|clt|clv|clz|com|cp|cpc|cpi|cpse|dec|des|eicall|eijmp|elpm|eor|fmul|fmuls|fmulsu|icall|ijmp|in|inc|jmp|lac|las|lat|ld|ld[a-z0-9]|lpm|lsl|lsr|mov|movw|mul|muls|mulsu|neg|nop|or|ori|out|pop|push|rcall|ret|reti|rjmp|rol|ror|sbc|sbci|sbi|sbic|sbis|sbiw|sbr|sbrc|sbrs|sec|seh|sei|sen|ser|ses|set|sev|sez|sleep|spm|st|st[a-zA-Z0-9]|sub|subi|swap|tst|wdr|xch)\b/,alias:"keyword"},"hex-number":{pattern:/#?\$[\da-f]{2,4}\b/i,alias:"number"},"binary-number":{pattern:/#?%[01]+\b/,alias:"number"},"decimal-number":{pattern:/#?\b\d+\b/,alias:"number"},register:{pattern:/\b[acznvshtixy]\b/i,alias:"variable"},operator:/>>=?|<<=?|&[&=]?|\|[\|=]?|[-+*/%^!=<>?]=?/,punctuation:/[(),:]/};
\ No newline at end of file
diff --git a/tests/languages/asmatmel/operator_feature.test b/tests/languages/asmatmel/operator_feature.test
index 75ae827d58..cf04ee945b 100644
--- a/tests/languages/asmatmel/operator_feature.test
+++ b/tests/languages/asmatmel/operator_feature.test
@@ -1,6 +1,13 @@
 OUT PORTB,x
 ldi r17,(1<<PD07)
 
++ - * / ^
++= -= *= /= ^=
+>> >>= << <<=
+& && &= | || |=
+< <= > >= != ==
+! = ? ?=
+
 ----------------------------------------------------
 
 [
@@ -16,7 +23,43 @@ ldi r17,(1<<PD07)
 	["decimal-number", "1"],
 	["operator", "<<"],
 	["constant", "PD07"],
-	["punctuation", ")"]
+	["punctuation", ")"],
+
+	["operator", "+"],
+	["operator", "-"],
+	["operator", "*"],
+	["operator", "/"],
+	["operator", "^"],
+
+	["operator", "+="],
+	["operator", "-="],
+	["operator", "*="],
+	["operator", "/="],
+	["operator", "^="],
+
+	["operator", ">>"],
+	["operator", ">>="],
+	["operator", "<<"],
+	["operator", "<<="],
+
+	["operator", "&"],
+	["operator", "&&"],
+	["operator", "&="],
+	["operator", "|"],
+	["operator", "||"],
+	["operator", "|="],
+
+	["operator", "<"],
+	["operator", "<="],
+	["operator", ">"],
+	["operator", ">="],
+	["operator", "!="],
+	["operator", "=="],
+
+	["operator", "!"],
+	["operator", "="],
+	["operator", "?"],
+	["operator", "?="]
 ]
 
 ----------------------------------------------------