diff --git a/src/cscout.cpp b/src/cscout.cpp
index 87fb13e..463cd34 100644
--- a/src/cscout.cpp
+++ b/src/cscout.cpp
@@ -1758,7 +1758,7 @@ explore_functions(FILE *fo, Call *f,
 		if (((*i)->*fbegin)() != ((*i)->*fend)()) {
 			/* Functions below; create +/- hyperlink. */
 			char param[1024];
-			sprintf(param, "f%02d%p", level, &(**i));
+			snprintf(param, sizeof(param), "f%02d%p", level, &(**i));
 			char *pval = swill_getvar(param);
 
 			if (pval) {
@@ -1829,14 +1829,14 @@ funlist_page(FILE *fo, void *p)
 		fbegin = &Call::caller_begin;
 		fend = &Call::caller_end;
 		fprintf(fo, "List of %s calling functions\n", calltype);
-		sprintf(buff, " &mdash; <a href=\"cpath%s?from=%%p&to=%p\">call path from function</a>", graph_suffix(), f);
+		snprintf(buff, sizeof(buff), " &mdash; <a href=\"cpath%s?from=%%p&to=%p\">call path from function</a>", graph_suffix(), f);
 		break;
 	case 'd':
 	case 'D':
 		fbegin = &Call::call_begin;
 		fend = &Call::call_end;
 		fprintf(fo, "List of %s called functions\n", calltype);
-		sprintf(buff, " &mdash; <a href=\"cpath%s?from=%p&to=%%p\">call path to function</a>", graph_suffix(), f);
+		snprintf(buff, sizeof(buff), " &mdash; <a href=\"cpath%s?from=%p&to=%%p\">call path to function</a>", graph_suffix(), f);
 		break;
 	}
 	if (swill_getvar("e")) {
@@ -3599,7 +3599,7 @@ main(int argc, char *argv[])
 		cout << Sql::getInterface()->end_commands();
 #ifdef LINUX_STAT_MONITOR
 		char buff[100];
-		sprintf(buff, "cat /proc/%u/stat >%u.stat", getpid(), getpid());
+		snprintf(buff, sizeof(buff), "cat /proc/%u/stat >%u.stat", getpid(), getpid());
 		if (system(buff) != 0) {
 			fprintf(stderr, "Unable to run %s\n", buff);
 			exit(1);
diff --git a/src/funquery.cpp b/src/funquery.cpp
index 5124488..f81af4a 100644
--- a/src/funquery.cpp
+++ b/src/funquery.cpp
@@ -161,7 +161,7 @@ FunQuery::param_url() const
 	if (id_ec) {
 		char buff[256];
 
-		sprintf(buff, "&ec=%p", id_ec);
+		snprintf(buff, sizeof(buff), "&ec=%p", id_ec);
 		r += buff;
 	} else {
 		r += "&match=";
@@ -169,11 +169,11 @@ FunQuery::param_url() const
 	}
 	r += mquery.param_url();
 	if (call) {
-		sprintf(buff, "&call=%p", call);
+		snprintf(buff, sizeof(buff), "&call=%p", call);
 		r += buff;
 	}
 	if (match_fid) {
-		sprintf(buff, "&fid=%d", fid.get_id());
+		snprintf(buff, sizeof(buff), "&fid=%d", fid.get_id());
 		r += buff;
 	}
 	if (cfun)
diff --git a/src/idquery.cpp b/src/idquery.cpp
index 1308798..40f1c07 100644
--- a/src/idquery.cpp
+++ b/src/idquery.cpp
@@ -192,7 +192,7 @@ IdQuery::param_url() const
 	if (ec) {
 		char buff[256];
 
-		sprintf(buff, "&ec=%p", ec);
+		snprintf(buff, sizeof(buff), "&ec=%p", ec);
 		r += buff;
 	} else {
 		r += "&match=";
diff --git a/src/md5.c b/src/md5.c
index f6b43a1..f181708 100644
--- a/src/md5.c
+++ b/src/md5.c
@@ -105,8 +105,8 @@ static unsigned char PADDING[64] = {
 /* The routine MD5Init initializes the message-digest context
    mdContext. All fields are set to zero.
  */
-void MD5Init (mdContext)
-MD5_CTX *mdContext;
+void
+MD5Init(MD5_CTX *mdContext)
 {
   mdContext->i[0] = mdContext->i[1] = (UINT4)0;
 
@@ -122,10 +122,8 @@ MD5_CTX *mdContext;
    account for the presence of each of the characters inBuf[0..inLen-1]
    in the message whose digest is being computed.
  */
-void MD5Update (mdContext, inBuf, inLen)
-MD5_CTX *mdContext;
-unsigned char *inBuf;
-unsigned int inLen;
+void
+MD5Update(MD5_CTX *mdContext, unsigned char *inBuf, unsigned int inLen)
 {
   UINT4 in[16];
   int mdi;
@@ -160,8 +158,8 @@ unsigned int inLen;
 /* The routine MD5Final terminates the message-digest computation and
    ends with the desired message digest in mdContext->digest[0...15].
  */
-void MD5Final (mdContext)
-MD5_CTX *mdContext;
+void
+MD5Final(MD5_CTX *mdContext)
 {
   UINT4 in[16];
   int mdi;
diff --git a/src/md5.h b/src/md5.h
index fbac623..efd5e0d 100644
--- a/src/md5.h
+++ b/src/md5.h
@@ -59,10 +59,10 @@ typedef struct {
   unsigned char digest[16];     /* actual digest after MD5Final call */
 } MD5_CTX;
 
-void MD5Init ();
-void MD5Update ();
-void MD5Final ();
-unsigned char * MD5File(const char *fname);
+void MD5Init(MD5_CTX *mdContext);
+void MD5Update(MD5_CTX *mdContext, unsigned char *inBuf, unsigned int inLen);
+void MD5Final(MD5_CTX *mdContext);
+unsigned char *MD5File(const char *fname);
 
 #ifdef __cplusplus
 }
diff --git a/src/option.cpp b/src/option.cpp
index 6c14242..bde6a68 100644
--- a/src/option.cpp
+++ b/src/option.cpp
@@ -75,8 +75,8 @@ BoolOption *Option::cgraph_dot_url;		// Include URLs in dot output
 vector<Option *> Option::options;		// Options in the order they were added
 map<string, Option *> Option::omap;		// For loading options
 
-SelectionOption::SelectionOption(const char *sn, const char *un, char iv, ...) :
-	Option(sn, un), v(iv)
+SelectionOption::SelectionOption(const char *sn, const char *un, int iv, ...) :
+	Option(sn, un), v((char)iv)
 {
 	va_list marker;
 	va_start(marker, iv);
diff --git a/src/option.h b/src/option.h
index 7049ce5..0e5f578 100644
--- a/src/option.h
+++ b/src/option.h
@@ -156,7 +156,7 @@ class SelectionOption : public Option {
 	 * Construct from name, short name, initial value, and a NULL-terminated list
 	 * list of arguments of the form "letter:Description"
 	 */
-	SelectionOption(const char *sn, const char *un, char iv, ...);
+	SelectionOption(const char *sn, const char *un, int iv, ...);
 	// Save to a file
 	void save(ofstream &ofs) const { ofs << v; }
 	// Load from a file
diff --git a/src/os.cpp b/src/os.cpp
index a0d5d0f..20db2f4 100644
--- a/src/os.cpp
+++ b/src/os.cpp
@@ -110,7 +110,7 @@ get_uniq_fname_string(const char *name)
 		 */
 		Error::error(E_FATAL, "Unable to stat file " + s, false);
 	}
-	sprintf(buff, "%ld:%ld", (long)sb.st_dev, (long)sb.st_ino);
+	snprintf(buff, sizeof(buff), "%ld:%ld", (long)sb.st_dev, (long)sb.st_ino);
 	if (DP())
 		cout << "uniq fname " << name << " = " << buff << "\n";
 	return (buff);
@@ -125,7 +125,7 @@ get_full_path(const char *name)
 	if (name[0] != '/') {
 		// Relative path
 		(void)getcwd(wd, sizeof(wd));
-		sprintf(buff, "%s/%s", wd, name);
+		snprintf(buff, sizeof(buff), "%s/%s", wd, name);
 		return (buff);
 	} else
 		return (name);
diff --git a/src/parse.y b/src/parse.y
index 7b03cee..2ef812c 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -2737,9 +2737,8 @@ yacc_variable:
 		}
 	| '$' INT_CONST
 		{
-			const char *num = $2.get_name().c_str();
 			char *endptr;
-			int val = strtol(num, &endptr, 0);
+			int val = strtol($2.get_name().c_str(), &endptr, 0);
 			if ((unsigned)val >= yacc_dollar.size()) {
 				/*
 				 * @error
diff --git a/src/pdtoken.cpp b/src/pdtoken.cpp
index ecff2f3..5bd2447 100644
--- a/src/pdtoken.cpp
+++ b/src/pdtoken.cpp
@@ -1070,8 +1070,7 @@ Pdtoken::process_pragma()
 			return;
 		}
 		char *endptr;
-		unsigned long offset = strtoul(t.get_val().c_str(), &endptr, 0);
-		offset += 0;	// silence the compiler warning
+		(void)strtoul(t.get_val().c_str(), &endptr, 0);
 		// XXX now do the work
 	} else if (t.get_val() == "nosync") {
 		// XXX now do the work
diff --git a/src/query.cpp b/src/query.cpp
index 8987876..a569b8c 100644
--- a/src/query.cpp
+++ b/src/query.cpp
@@ -60,7 +60,7 @@ Query::url(const string &s)
 		else {
 			char buff[4];
 
-			sprintf(buff, "%%%02x", (unsigned)*i);
+			snprintf(buff, sizeof(buff), "%%%02x", (unsigned)*i);
 			r += buff;
 		}
 	return r;