diff --git a/src/ks_gbfhtml.cpp b/src/ks_gbfhtml.cpp
index f8f2a8d..f31ce7a 100644
--- a/src/ks_gbfhtml.cpp
+++ b/src/ks_gbfhtml.cpp
@@ -176,10 +176,10 @@ namespace KioSword {
 			else if (!strcmp(tag.getName(), "RF")) {
 				SWBuf type = tag.getAttribute("type");
 				SWBuf footnoteNumber = tag.getAttribute("swordFootnote");
-				VerseKey *vkey;
+				const VerseKey *vkey;
 				// see if we have a VerseKey * or descendant
 				try {
-					vkey = SWDYNAMIC_CAST(VerseKey, u->key);
+					vkey = SWDYNAMIC_CAST(const VerseKey, u->key);
 				}
 				catch ( ... ) {	}
 				if (vkey) {
diff --git a/src/ks_osishtml.cpp b/src/ks_osishtml.cpp
index 6bda142..1f4dadc 100644
--- a/src/ks_osishtml.cpp
+++ b/src/ks_osishtml.cpp
@@ -157,10 +157,10 @@ namespace KioSword {
 	
 						if (type != "strongsMarkup") {	// leave strong's markup notes out, in the future we'll probably have different option filters to turn different note types on or off
 							SWBuf footnoteNumber = tag.getAttribute("swordFootnote");
-							VerseKey *vkey;
+							const VerseKey *vkey;
 							// see if we have a VerseKey * or descendant
 							try {
-								vkey = SWDYNAMIC_CAST(VerseKey, u->key);
+								vkey = SWDYNAMIC_CAST(const VerseKey, u->key);
 							}
 							catch ( ... ) {	}
 							if (vkey) {
diff --git a/src/ks_thmlhtml.cpp b/src/ks_thmlhtml.cpp
index 6dc51be..568a6d4 100644
--- a/src/ks_thmlhtml.cpp
+++ b/src/ks_thmlhtml.cpp
@@ -104,10 +104,10 @@ namespace KioSword {
 					if (!tag.isEmpty()) {
 						SWBuf type = tag.getAttribute("type");
 						SWBuf footnoteNumber = tag.getAttribute("swordFootnote");
-						VerseKey *vkey;
+						const VerseKey *vkey;
 						// see if we have a VerseKey * or descendant
 						try {
-							vkey = SWDYNAMIC_CAST(VerseKey, u->key);
+							vkey = SWDYNAMIC_CAST(const VerseKey, u->key);
 						}
 						catch ( ... ) {	}
 						if (vkey) {
@@ -150,10 +150,10 @@ namespace KioSword {
 					// FIXME for Kio-Sword
 					else {
 						SWBuf footnoteNumber = u->startTag.getAttribute("swordFootnote");
-						VerseKey *vkey;
+						const VerseKey *vkey;
 						// see if we have a VerseKey * or descendant
 						try {
-							vkey = SWDYNAMIC_CAST(VerseKey, u->key);
+							vkey = SWDYNAMIC_CAST(const VerseKey, u->key);
 						}
 						catch ( ... ) {}
 						if (vkey) {