diff --git a/src/burp/burp.h b/src/burp/burp.h
index 3fb58a76b9e..d9fa2ae4eae 100644
--- a/src/burp/burp.h
+++ b/src/burp/burp.h
@@ -708,6 +708,7 @@ enum att_type {
 // Trigger types
 
 enum trig_t {
+	trig_none = 0,
 	trig_pre_store = 1,   // default
 	trig_pre_modify,	  // default
 	trig_post_erase	   // default
diff --git a/src/burp/restore.epp b/src/burp/restore.epp
index aa36e72a748..fa68cc935be 100644
--- a/src/burp/restore.epp
+++ b/src/burp/restore.epp
@@ -31,6 +31,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <errno.h>
+#include <limits.h>
 #ifdef HAVE_CTYPE_H
 #include <ctype.h>
 #endif
@@ -1608,7 +1609,7 @@ bool get_acl(BurpGlobals* tdgbl, const TEXT* owner_nm, ISC_QUAD* blob_id, ISC_QU
 
 	ULONG length = 0;
 	UCHAR item;
-	USHORT max_segment;
+	USHORT max_segment = USHRT_MAX;
 	ULONG num_segments;
 	const UCHAR* p = blob_info;
 
@@ -1783,7 +1784,7 @@ void get_array(BurpGlobals* tdgbl, burp_rel* relation, UCHAR* record_buffer)
 	SLONG		fld_ranges[2 * MAX_DIMENSION];
 	SLONG       slice_length = 0;
 	SLONG       *range;
-	const SLONG* end_ranges;
+	const SLONG* end_ranges = fld_ranges;
 	scan_attr_t scan_next_attr;
 	skip_init(&scan_next_attr);
 	att_type	attribute;
@@ -1851,7 +1852,6 @@ void get_array(BurpGlobals* tdgbl, burp_rel* relation, UCHAR* record_buffer)
 	SLONG last_element_dim[MAX_DIMENSION];
 	if (return_length != slice_length)
 	{
-		int upper, lower;
 		//
 		// Ugh!  The full array wasn't returned and versions of gbak prior to
 		// V3.2I don't explicitly signal this.  We must recompute the top
@@ -1974,6 +1974,8 @@ void get_array(BurpGlobals* tdgbl, burp_rel* relation, UCHAR* record_buffer)
 			// dims were (1,2), we would just do a isc_put_slice(1..1, 1..2).
 			// This is applied for any number of dimensions.
 			//
+
+			int upper = 0, lower = 0;
 			for (range = field->fld_ranges, count = 0; range < end_ranges; range += 2, count++)
 			{
 				add_byte(blr, isc_sdl_do2);
@@ -3386,7 +3388,7 @@ void get_data(BurpGlobals* tdgbl, burp_rel* relation, WriteRelationReq* req)
 					}
 				}
 
-				UCHAR* p;
+				UCHAR* p = nullptr;
 				if (tdgbl->gbl_sw_transportable)
 				{
 					if (get(tdgbl) != att_xdr_length)
@@ -9096,9 +9098,10 @@ bool get_db_creator(BurpGlobals* tdgbl)
  **************************************/
 	att_type		attribute;
 	scan_attr_t		scan_next_attr;
-	TEXT			usr[GDS_NAME_LEN];
-	SSHORT			uType;
-	bool			userSet, typeSet;
+	TEXT			usr[GDS_NAME_LEN] = {0};
+	SSHORT			uType = 0;
+	bool			userSet = false;
+	bool			typeSet = false;
 
 	userSet = typeSet = false;
 
@@ -9422,7 +9425,7 @@ bool get_trigger_old (BurpGlobals* tdgbl, burp_rel* relation)
  *	Get a trigger definition for a relation.
  *
  **************************************/
-	enum trig_t	type;
+	enum trig_t	type = trig_none;
 	att_type	attribute;
 	TEXT		name[GDS_NAME_LEN];
 	scan_attr_t		scan_next_attr;
diff --git a/src/dsql/DdlNodes.epp b/src/dsql/DdlNodes.epp
index 8bdb8c9b184..66f62f1ec61 100644
--- a/src/dsql/DdlNodes.epp
+++ b/src/dsql/DdlNodes.epp
@@ -227,7 +227,8 @@ static void checkForeignKeyTempScope(thread_db* tdbb, jrd_tra* transaction,
 {
 	AutoCacheRequest request(tdbb, drq_l_rel_info, DYN_REQUESTS);
 	QualifiedName masterRelName;
-	rel_t masterType, childType;
+	rel_t masterType = rel_persistent;
+	rel_t childType = rel_persistent;
 
 	FOR(REQUEST_HANDLE request TRANSACTION_HANDLE transaction)
 		RLC_M IN RDB$RELATION_CONSTRAINTS CROSS
diff --git a/src/jrd/cvt2.cpp b/src/jrd/cvt2.cpp
index 81ca4658ce8..94736deb039 100644
--- a/src/jrd/cvt2.cpp
+++ b/src/jrd/cvt2.cpp
@@ -973,7 +973,7 @@ USHORT CVT2_make_string2(const dsc* desc, TTypeId to_interp, UCHAR** address, Mo
  **************************************/
 	UCHAR* from_buf;
 	USHORT from_len;
-	TTypeId from_interp;
+	TTypeId from_interp = ttype_none;
 
 	fb_assert(desc != NULL);
 	fb_assert(address != NULL);
@@ -1004,7 +1004,7 @@ USHORT CVT2_make_string2(const dsc* desc, TTypeId to_interp, UCHAR** address, Mo
 
 	if (desc->isText())
 	{
-		if (from_interp == to_interp || to_interp == ttype_none || to_interp == ttype_binary)
+		if (from_interp == ttype_none || from_interp == to_interp || to_interp == ttype_none || to_interp == ttype_binary)
 		{
 			*address = from_buf;
 			return from_len;
diff --git a/src/jrd/os/posix/unix.cpp b/src/jrd/os/posix/unix.cpp
index 780eeb90500..3b276f4cdfc 100644
--- a/src/jrd/os/posix/unix.cpp
+++ b/src/jrd/os/posix/unix.cpp
@@ -533,7 +533,7 @@ bool PIO_header(thread_db* tdbb, UCHAR* address, unsigned length)
 	const auto dbb = tdbb->getDatabase();
 
 	unsigned i;
-	SINT64 bytes;
+	SINT64 bytes = 0;
 
 	PageSpace* const pageSpace = dbb->dbb_page_manager.findPageSpace(DB_PAGE_SPACE);
 	jrd_file* const file = pageSpace->file;
diff --git a/src/remote/client/interface.cpp b/src/remote/client/interface.cpp
index 731b68266ec..c9f65bf9e19 100644
--- a/src/remote/client/interface.cpp
+++ b/src/remote/client/interface.cpp
@@ -2011,7 +2011,7 @@ unsigned char* Attachment::getLocalInfo(UCharBuffer& info, unsigned int buffer_l
 			break;
 		}
 
-		FB_UINT64 value;
+		FB_UINT64 value = 0;
 		bool skip = false;
 
 		switch (*item)