diff --git a/engines/glk/tads/tads2/output.cpp b/engines/glk/tads/tads2/output.cpp
index 79284b7b924..5f7e46b70be 100644
--- a/engines/glk/tads/tads2/output.cpp
+++ b/engines/glk/tads/tads2/output.cpp
@@ -2448,7 +2448,7 @@ static int outformatlen_stream(out_stream_info *stream,
                          || !scumm_stricmp(tagbuf, "em")
                          || !scumm_stricmp(tagbuf, "strong"))
                 {
-                    int attr;
+                    int attr = 0;
                     
                     /* choose the attribute flag */
                     switch (tagbuf[0])
diff --git a/engines/glk/tads/tads2/run.cpp b/engines/glk/tads/tads2/run.cpp
index 64b52a4d79d..0def6a771be 100644
--- a/engines/glk/tads/tads2/run.cpp
+++ b/engines/glk/tads/tads2/run.cpp
@@ -1096,15 +1096,19 @@ void runexe(runcxdef *ctx, uchar *p0, objnum self, objnum target,
 	runsdef   val;                           /* stack element (for pushing) */
 	runsdef   val2;     /* another one (for popping in two-op instructions) */
 	uint      ofs;                   /* offset in code of current execution */
-	prpnum    prop;                         /* property number, when needed */
-	objnum    obj;                            /* object number, when needed */
+	prpnum    prop = 0;                     /* property number, when needed */
+	objnum    obj = 0;                        /* object number, when needed */
 	runsdef  *noreg rstsp;        /* sp to reset to on DISCARD instructions */
-	uchar    *lstp;                                         /* list pointer */
+	uchar    *lstp = nullptr;                               /* list pointer */
 	int       nargc;                   /* argument count of called function */
 	runsdef  *valp;
 	runsdef  *stkval;
-	int       i;
+	int       i = 0;
 	int       brkchk;
+	runsdef  val3;
+	int      asityp;
+	int      asiext = 0;
+	int      lclnum = 0;
 
 #ifndef DBG_OFF
 	int       err;
@@ -1954,11 +1958,6 @@ resume_from_error:
 			default:
 				if ((opc & OPCASI_MASK) == OPCASI_MASK)
 				{
-					runsdef  val3;
-					int      asityp;
-					int      asiext;
-					int      lclnum;
-
 					valp = &val;
 					stkval = &val;
 
diff --git a/engines/glk/tads/tads2/run.h b/engines/glk/tads/tads2/run.h
index 0a39fca4e2d..8b7c5905fca 100644
--- a/engines/glk/tads/tads2/run.h
+++ b/engines/glk/tads/tads2/run.h
@@ -57,7 +57,11 @@ struct runsdef {
         objnum  runsvobj;                                   /* object value */
         prpnum  runsvprp;                          /* property number value */
         uchar  *runsvstr;                              /* string/list value */
-    } runsv;
+	} runsv;
+
+	runsdef() : runstyp(0) {
+		runsv.runsvnum = 0;
+	}
 };
 
 /* external function control structure */