diff --git a/util/ego/cs/cs_profit.c b/util/ego/cs/cs_profit.c
index 2efabcb03..801e34319 100644
--- a/util/ego/cs/cs_profit.c
+++ b/util/ego/cs/cs_profit.c
@@ -72,7 +72,7 @@ void cs_machinit(void *vp)
 	/* Find piece that is relevant for this phase. */
 	do {
 		while (getc(f) != '\n');
-		fscanf(f, "%s", s);
+		fscanf(f, "%99s", s);
 	} while (strcmp(s, "%%CS"));
 
 	/* Choose a set of instructions which must only be eliminated
diff --git a/util/ego/ra/makeitems.c b/util/ego/ra/makeitems.c
index bd9cf35f4..83f6703bd 100644
--- a/util/ego/ra/makeitems.c
+++ b/util/ego/ra/makeitems.c
@@ -32,14 +32,14 @@ convert(mnemfile,itemfile)
 	newcl = TRUE;
 	printf("struct item_descr itemtab[] = {\n");
 	for (;;) {
-		fscanf(mnemfile,"%s%s%d",def,mnem1,&opc);
+		fscanf(mnemfile,"%19s%19s%d",def,mnem1,&opc);
 		/* read a line like "#define op_aar 1" */
 		if (feof(mnemfile)) break;
 		if (strcmp(def,"#define") != 0) {
 			error("bad mnemonic file, #define expected");
 		}
 		if (newcl) {
-			fscanf(itemfile,"%s%s%d",mnem2,itemtype,&index);
+			fscanf(itemfile,"%19s%19s%d",mnem2,itemtype,&index);
 			/* read a line like "op_loc CONST 4" */
 		}
 		if (feof(itemfile) || strcmp(mnem1,mnem2) != 0) {
diff --git a/util/ego/ra/ra.c b/util/ego/ra/ra.c
index 643831f8d..0b1d5e493 100644
--- a/util/ego/ra/ra.c
+++ b/util/ego/ra/ra.c
@@ -112,7 +112,7 @@ STATIC void ra_machinit(void *vp)
 
 	for (;;) {
 		while(getc(f) != '\n');
-		fscanf(f,"%s",s);
+		fscanf(f,"%99s",s);
 		if (strcmp(s,"%%RA") == 0)break;
 	}
 	fscanf(f,"%hd",&regs_available[reg_any]);
diff --git a/util/ego/share/makecldef.c b/util/ego/share/makecldef.c
index a89d30538..2913e26f5 100644
--- a/util/ego/share/makecldef.c
+++ b/util/ego/share/makecldef.c
@@ -37,14 +37,14 @@ convert(mnemfile,classfile)
 	printf("\tNOCLASS,\tNOCLASS,\n");
 	/* EM mnemonics start at 1, arrays in C at 0 */
 	for (;;) {
-		fscanf(mnemfile,"%s%s%d",def,mnem1,&opc);
+		fscanf(mnemfile,"%9s%9s%d",def,mnem1,&opc);
 		/* read a line like "#define op_aar 1" */
 		if (feof(mnemfile)) break;
 		if (strcmp(def,"#define") != 0) {
 			error("bad mnemonic file, #define expected");
 		}
 		if (newcl) {
-			fscanf(classfile,"%s%d%d",mnem2,&src,&res);
+			fscanf(classfile,"%9s%d%d",mnem2,&src,&res);
 			/* read a line like "op_loc 8 1" */
 		}
 		if (feof(classfile) || strcmp(mnem1,mnem2) != 0) {
diff --git a/util/ego/sp/sp.c b/util/ego/sp/sp.c
index 051281d7e..0ba323a10 100644
--- a/util/ego/sp/sp.c
+++ b/util/ego/sp/sp.c
@@ -60,7 +60,7 @@ STATIC void sp_machinit(void *vp)
 
 	for (;;) {
 		while(getc(f) != '\n');
-		fscanf(f,"%s",s);
+		fscanf(f,"%99s",s);
 		if (strcmp(s,"%%SP") == 0)break;
 	}
 	fscanf(f,"%d",&globl_sp_allowed);
diff --git a/util/ego/sr/sr.c b/util/ego/sr/sr.c
index e933cb0de..bdfedef01 100644
--- a/util/ego/sr/sr.c
+++ b/util/ego/sr/sr.c
@@ -61,7 +61,7 @@ void sr_machinit(void *vp)
 
 	for (;;) {
 		while(getc(f) != '\n');
-		fscanf(f,"%s",s);
+		fscanf(f,"%99s",s);
 		if (strcmp(s,"%%SR") == 0)break;
 	}
 	fscanf(f,"%d",&ovfl_harmful);
diff --git a/util/ego/ud/ud.c b/util/ego/ud/ud.c
index 087337144..6afcd5c2b 100644
--- a/util/ego/ud/ud.c
+++ b/util/ego/ud/ud.c
@@ -64,7 +64,7 @@ STATIC void ud_machinit(void *vp)
 
 	for (;;) {
 		while(getc(f) != '\n');
-		fscanf(f,"%s",s);
+		fscanf(f,"%99s",s);
 		if (strcmp(s,"%%UD") == 0)break;
 	}
 	globl_cond_tab = getcondtab(f);
diff --git a/util/int/switch/mkiswitch.c b/util/int/switch/mkiswitch.c
index b9676d237..8be3d54a9 100644
--- a/util/int/switch/mkiswitch.c
+++ b/util/int/switch/mkiswitch.c
@@ -52,7 +52,7 @@ main(argc, argv)
 	}
 
 	/* Start reading the input file */
-	while (fscanf(ifp, "%s %s", mnem, flgs) >= 0) {
+	while (fscanf(ifp, "%7s %7s", mnem, flgs) >= 0) {
 		int i;
 		char *p;
 		char *base;
diff --git a/util/int/switch/mkswitch.c b/util/int/switch/mkswitch.c
index 01446bd95..2ada08a3c 100644
--- a/util/int/switch/mkswitch.c
+++ b/util/int/switch/mkswitch.c
@@ -55,7 +55,7 @@ main(argc, argv)
 	}
 
 	/* Start reading the input file */
-	while (fscanf(ifp, "%s %s", mnem, flgs) >= 0) {
+	while (fscanf(ifp, "%7s %7s", mnem, flgs) >= 0) {
 		int i;
 		char *p;
 		char *base;