diff --git a/include/asm/fstack.h b/include/asm/fstack.h
index f3e8a878..627c8325 100644
--- a/include/asm/fstack.h
+++ b/include/asm/fstack.h
@@ -35,7 +35,7 @@ struct sContext {
 	uint32_t nREPTBlockSize;
 };
 
-extern unsigned int nMaxFileStackDepth;
+extern unsigned int nMaxRecursionDepth;
 
 void fstk_RunInclude(char *tzFileName);
 void fstk_RunMacroArg(int32_t s);
diff --git a/include/asm/lexer.h b/include/asm/lexer.h
index 3a86a773..c4e845b5 100644
--- a/include/asm/lexer.h
+++ b/include/asm/lexer.h
@@ -40,6 +40,13 @@ enum eLexerState {
 	LEX_STATE_MACROARGS
 };
 
+struct sStringExpansionPos {
+	char *tzName;
+	char *pBuffer;
+	char *pBufferPos;
+	struct sStringExpansionPos *pParent;
+};
+
 #define INITIAL		0
 #define macroarg	3
 
@@ -62,6 +69,7 @@ void lex_FloatDeleteSecondRange(uint32_t id, uint16_t start, uint16_t end);
 void lex_Init(void);
 void lex_AddStrings(const struct sLexInitString *lex);
 void lex_SetBuffer(char *buffer, uint32_t len);
+void lex_BeginStringExpansion(const char *tzName);
 int yywrap(void);
 int yylex(void);
 void yyunput(char c);
@@ -70,6 +78,7 @@ void yyskipbytes(uint32_t count);
 void yyunputbytes(uint32_t count);
 
 extern YY_BUFFER_STATE pCurrentBuffer;
+extern struct sStringExpansionPos *pCurrentStringExpansion;
 
 void upperstring(char *s);
 void lowerstring(char *s);
diff --git a/src/asm/fstack.c b/src/asm/fstack.c
index b471cdd6..fbe1459c 100644
--- a/src/asm/fstack.c
+++ b/src/asm/fstack.c
@@ -29,7 +29,7 @@
 
 static struct sContext *pFileStack;
 static unsigned int nFileStackDepth;
-unsigned int nMaxFileStackDepth;
+unsigned int nMaxRecursionDepth;
 static struct sSymbol *pCurrentMacro;
 static YY_BUFFER_STATE CurrentFlexHandle;
 static FILE *pCurrentFile;
@@ -62,8 +62,8 @@ static void pushcontext(void)
 {
 	struct sContext **ppFileStack;
 
-	if (++nFileStackDepth > nMaxFileStackDepth)
-		fatalerror("Recursion limit (%d) exceeded", nMaxFileStackDepth);
+	if (++nFileStackDepth > nMaxRecursionDepth)
+		fatalerror("Recursion limit (%d) exceeded", nMaxRecursionDepth);
 
 	ppFileStack = &pFileStack;
 	while (*ppFileStack)
diff --git a/src/asm/globlex.c b/src/asm/globlex.c
index 98786a34..066cd9d1 100644
--- a/src/asm/globlex.c
+++ b/src/asm/globlex.c
@@ -279,6 +279,8 @@ uint32_t ParseSymbol(char *src, uint32_t size)
 	if (!oDontExpandStrings && sym_isString(dest)) {
 		char *s;
 
+		lex_BeginStringExpansion(dest);
+
 		/* Feed the symbol's contents into the buffer */
 		yyunputstr(s = sym_GetStringValue(dest));
 
diff --git a/src/asm/lexer.c b/src/asm/lexer.c
index cdaaaf55..212a1f06 100644
--- a/src/asm/lexer.c
+++ b/src/asm/lexer.c
@@ -51,6 +51,9 @@ uint32_t tFloatingChars[256];
 uint32_t nFloating;
 enum eLexerState lexerstate = LEX_STATE_NORMAL;
 
+struct sStringExpansionPos *pCurrentStringExpansion;
+static unsigned int nNbStringExpansions;
+
 /* UTF-8 byte order mark */
 static const unsigned char bom[BOM_SIZE] = { 0xEF, 0xBB, 0xBF };
 
@@ -102,6 +105,31 @@ void yyunputstr(const char *s)
 	memcpy(pLexBuffer, s, len);
 }
 
+/*
+ * Marks that a new string expansion with name `tzName` ends here
+ * Enforces recursion depth
+ */
+void lex_BeginStringExpansion(const char *tzName)
+{
+	if (++nNbStringExpansions > nMaxRecursionDepth)
+		fatalerror("Recursion limit (%d) exceeded", nMaxRecursionDepth);
+
+	struct sStringExpansionPos *pNewStringExpansion =
+		malloc(sizeof(*pNewStringExpansion));
+	char *tzNewExpansionName = strdup(tzName);
+
+	if (!pNewStringExpansion || !tzNewExpansionName)
+		fatalerror("Could not allocate memory to expand '%s'",
+			   tzName);
+
+	pNewStringExpansion->tzName = tzNewExpansionName;
+	pNewStringExpansion->pBuffer = pLexBufferRealStart;
+	pNewStringExpansion->pBufferPos = pLexBuffer;
+	pNewStringExpansion->pParent = pCurrentStringExpansion;
+
+	pCurrentStringExpansion = pNewStringExpansion;
+}
+
 void yy_switch_to_buffer(YY_BUFFER_STATE buf)
 {
 	pCurrentBuffer = buf;
@@ -424,6 +452,9 @@ void lex_Init(void)
 
 	nLexMaxLength = 0;
 	nFloating = 0;
+
+	pCurrentStringExpansion = NULL;
+	nNbStringExpansions = 0;
 }
 
 void lex_AddStrings(const struct sLexInitString *lex)
@@ -968,12 +999,30 @@ static uint32_t yylex_MACROARGS(void)
 
 int yylex(void)
 {
+	int returnedChar;
 	switch (lexerstate) {
 	case LEX_STATE_NORMAL:
-		return yylex_NORMAL();
+		returnedChar = yylex_NORMAL();
+		break;
 	case LEX_STATE_MACROARGS:
-		return yylex_MACROARGS();
+		returnedChar = yylex_MACROARGS();
+		break;
 	default:
 		fatalerror("%s: Internal error.", __func__);
 	}
+
+	/* Check if string expansions were fully read */
+	while (pCurrentStringExpansion
+	    && pCurrentStringExpansion->pBuffer == pLexBufferRealStart
+	    && pCurrentStringExpansion->pBufferPos <= pLexBuffer) {
+		struct sStringExpansionPos *pParent =
+			pCurrentStringExpansion->pParent;
+		free(pCurrentStringExpansion->tzName);
+		free(pCurrentStringExpansion);
+
+		pCurrentStringExpansion = pParent;
+		nNbStringExpansions--;
+	}
+
+	return returnedChar;
 }
diff --git a/src/asm/main.c b/src/asm/main.c
index 0d928e92..a1829347 100644
--- a/src/asm/main.c
+++ b/src/asm/main.c
@@ -315,7 +315,7 @@ int main(int argc, char *argv[])
 
 	/* yydebug=1; */
 
-	nMaxFileStackDepth = 64;
+	nMaxRecursionDepth = 64;
 
 	DefaultOptions.gbgfx[0] = '0';
 	DefaultOptions.gbgfx[1] = '1';
@@ -389,7 +389,7 @@ int main(int argc, char *argv[])
 
 			break;
 		case 'r':
-			nMaxFileStackDepth = strtoul(optarg, &ep, 0);
+			nMaxRecursionDepth = strtoul(optarg, &ep, 0);
 
 			if (optarg[0] == '\0' || *ep != '\0')
 				errx(1, "Invalid argument for option 'r'");