diff --git a/c/qrcodegen.c b/c/qrcodegen.c
index 8f6de55..79bf810 100644
--- a/c/qrcodegen.c
+++ b/c/qrcodegen.c
@@ -528,7 +528,7 @@ static void drawFormatBits(enum qrcodegen_Ecc ecl, enum qrcodegen_Mask mask, uin
 	
 	// Draw second copy
 	int qrsize = qrcodegen_getSize(qrcode);
-	for (int i = 0; i <= 7; i++)
+	for (int i = 0; i < 8; i++)
 		setModule(qrcode, qrsize - 1 - i, 8, getBit(bits, i));
 	for (int i = 8; i < 15; i++)
 		setModule(qrcode, 8, qrsize - 15 + i, getBit(bits, i));
diff --git a/cpp/QrCode.cpp b/cpp/QrCode.cpp
index 0a8b12f..5005949 100644
--- a/cpp/QrCode.cpp
+++ b/cpp/QrCode.cpp
@@ -243,7 +243,7 @@ void QrCode::drawFormatBits(int mask) {
 		setFunctionModule(14 - i, 8, getBit(bits, i));
 	
 	// Draw second copy
-	for (int i = 0; i <= 7; i++)
+	for (int i = 0; i < 8; i++)
 		setFunctionModule(size - 1 - i, 8, getBit(bits, i));
 	for (int i = 8; i < 15; i++)
 		setFunctionModule(8, size - 15 + i, getBit(bits, i));
diff --git a/java/io/nayuki/qrcodegen/QrCode.java b/java/io/nayuki/qrcodegen/QrCode.java
index eba69ec..e689955 100644
--- a/java/io/nayuki/qrcodegen/QrCode.java
+++ b/java/io/nayuki/qrcodegen/QrCode.java
@@ -396,7 +396,7 @@ public final class QrCode {
 			setFunctionModule(14 - i, 8, getBit(bits, i));
 		
 		// Draw second copy
-		for (int i = 0; i <= 7; i++)
+		for (int i = 0; i < 8; i++)
 			setFunctionModule(size - 1 - i, 8, getBit(bits, i));
 		for (int i = 8; i < 15; i++)
 			setFunctionModule(8, size - 15 + i, getBit(bits, i));
diff --git a/javascript/qrcodegen.js b/javascript/qrcodegen.js
index 520daad..16531a5 100644
--- a/javascript/qrcodegen.js
+++ b/javascript/qrcodegen.js
@@ -257,7 +257,7 @@ var qrcodegen = new function() {
 				setFunctionModule(14 - i, 8, getBit(bits, i));
 			
 			// Draw second copy
-			for (var i = 0; i <= 7; i++)
+			for (var i = 0; i < 8; i++)
 				setFunctionModule(size - 1 - i, 8, getBit(bits, i));
 			for (var i = 8; i < 15; i++)
 				setFunctionModule(8, size - 15 + i, getBit(bits, i));
diff --git a/typescript/qrcodegen.ts b/typescript/qrcodegen.ts
index e2c1964..fe17bcd 100644
--- a/typescript/qrcodegen.ts
+++ b/typescript/qrcodegen.ts
@@ -337,7 +337,7 @@ namespace qrcodegen {
 				this.setFunctionModule(14 - i, 8, getBit(bits, i));
 			
 			// Draw second copy
-			for (let i = 0; i <= 7; i++)
+			for (let i = 0; i < 8; i++)
 				this.setFunctionModule(this.size - 1 - i, 8, getBit(bits, i));
 			for (let i = 8; i < 15; i++)
 				this.setFunctionModule(8, this.size - 15 + i, getBit(bits, i));