diff --git a/parser.go b/parser.go
index d7a5d0b..55dd3dc 100644
--- a/parser.go
+++ b/parser.go
@@ -1069,7 +1069,7 @@ func (p *Parser) parseShowMeasurementsStatement() (*ShowMeasurementsStatement, e
 			stmt.Database = lit
 		} else if tok == MUL {
 			stmt.WildcardDatabase = true
-		} else{
+		} else {
 			return nil, newParseError(tokstr(tok, lit), []string{"identifier or *"}, pos)
 		}
 
@@ -1079,7 +1079,7 @@ func (p *Parser) parseShowMeasurementsStatement() (*ShowMeasurementsStatement, e
 				stmt.RetentionPolicy = lit
 			} else if tok == MUL {
 				stmt.WildcardRetentionPolicy = true
-			} else{
+			} else {
 				return nil, newParseError(tokstr(tok, lit), []string{"identifier or *"}, pos)
 			}
 		} else {
@@ -2995,8 +2995,8 @@ func ParseDuration(s string) (time.Duration, error) {
 		i++
 	}
 
-	var measure int64
 	var unit string
+	var unitDuration time.Duration
 
 	// Parsing loop.
 	for i < len(a) {
@@ -3016,7 +3016,6 @@ func ParseDuration(s string) (time.Duration, error) {
 		if err != nil {
 			return 0, ErrInvalidDuration
 		}
-		measure = n
 
 		// Extract the unit of measure.
 		// If the last two characters are "ms" then parse as milliseconds.
@@ -3026,40 +3025,41 @@ func ParseDuration(s string) (time.Duration, error) {
 		case 'n':
 			if i+1 < len(a) && a[i+1] == 's' {
 				unit = string(a[i : i+2])
-				d += time.Duration(n)
-				i += 2
-				continue
+				unitDuration = time.Nanosecond
+				break
 			}
 			return 0, ErrInvalidDuration
 		case 'u', 'µ':
-			d += time.Duration(n) * time.Microsecond
+			unitDuration = time.Microsecond
 		case 'm':
 			if i+1 < len(a) && a[i+1] == 's' {
 				unit = string(a[i : i+2])
-				d += time.Duration(n) * time.Millisecond
-				i += 2
-				continue
+				unitDuration = time.Millisecond
+				break
 			}
-			d += time.Duration(n) * time.Minute
+			unitDuration = time.Minute
 		case 's':
-			d += time.Duration(n) * time.Second
+			unitDuration = time.Second
 		case 'h':
-			d += time.Duration(n) * time.Hour
+			unitDuration = time.Hour
 		case 'd':
-			d += time.Duration(n) * 24 * time.Hour
+			unitDuration = 24 * time.Hour
 		case 'w':
-			d += time.Duration(n) * 7 * 24 * time.Hour
+			unitDuration = 7 * 24 * time.Hour
 		default:
 			return 0, ErrInvalidDuration
 		}
-		i++
-	}
-
-	// Check to see if we overflowed a duration
-	if d < 0 && !isNegative {
-		return 0, fmt.Errorf("overflowed duration %d%s: choose a smaller duration or INF", measure, unit)
+		// Check to see if we overflowed a duration
+		if n > (1<<63-1)/unitDuration.Nanoseconds() {
+			return 0, fmt.Errorf("overflowed duration %s: choose a smaller duration or INF", s)
+		}
+		d += time.Duration(n) * unitDuration
+		// Check to see if we overflowed a duration
+		if d < 0 {
+			return 0, fmt.Errorf("overflowed duration %s: choose a smaller duration or INF", s)
+		}
+		i += len(unit)
 	}
-
 	if isNegative {
 		d = -d
 	}
diff --git a/parser_test.go b/parser_test.go
index e425694..d2cf9ba 100644
--- a/parser_test.go
+++ b/parser_test.go
@@ -1957,7 +1957,7 @@ func TestParser_ParseStatement(t *testing.T) {
 		{
 			s: `SHOW MEASUREMENTS ON db0.rp0`,
 			stmt: &influxql.ShowMeasurementsStatement{
-				Database: "db0",
+				Database:        "db0",
 				RetentionPolicy: "rp0",
 			},
 		},
@@ -1974,7 +1974,7 @@ func TestParser_ParseStatement(t *testing.T) {
 		{
 			s: `SHOW MEASUREMENTS ON *.*`,
 			stmt: &influxql.ShowMeasurementsStatement{
-				WildcardDatabase: true,
+				WildcardDatabase:        true,
 				WildcardRetentionPolicy: true,
 			},
 		},
@@ -1983,7 +1983,7 @@ func TestParser_ParseStatement(t *testing.T) {
 		{
 			s: `SHOW MEASUREMENTS ON db0.*`,
 			stmt: &influxql.ShowMeasurementsStatement{
-				Database: "db0",
+				Database:                "db0",
 				WildcardRetentionPolicy: true,
 			},
 		},
@@ -1992,7 +1992,7 @@ func TestParser_ParseStatement(t *testing.T) {
 		{
 			s: `SHOW MEASUREMENTS ON *.rp0`,
 			stmt: &influxql.ShowMeasurementsStatement{
-				RetentionPolicy: "rp0",
+				RetentionPolicy:  "rp0",
 				WildcardDatabase: true,
 			},
 		},
@@ -4171,6 +4171,10 @@ func TestParseDuration(t *testing.T) {
 		{s: `1.2w`, err: "invalid duration"},
 		{s: `10x`, err: "invalid duration"},
 		{s: `10n`, err: "invalid duration"},
+
+		{s: `99999999999h`, err: overflowErrString(`99999999999h`)},
+		{s: `2562047h50m`, err: overflowErrString(`2562047h50m`)},
+		{s: `-2562047h47m50s`, err: overflowErrString(`-2562047h47m50s`)},
 	}
 
 	for i, tt := range tests {
@@ -4183,6 +4187,10 @@ func TestParseDuration(t *testing.T) {
 	}
 }
 
+func overflowErrString(s string) string {
+	return fmt.Sprintf("overflowed duration %s: choose a smaller duration or INF", s)
+}
+
 // Ensure a time duration can be formatted.
 func TestFormatDuration(t *testing.T) {
 	var tests = []struct {